Transportation and Energy Systems in the U.S.

Working Paper

TRANSPORTATION AND

ENERGY SYSTEMS IN THE U.S.

N. Nakicenovic

WP-87-001 January 1987

FllASA

International Institute for Applied Systems Analysis A-2361 Laxenburg Austria

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Telephone: (0 2 2 3 6 ) 715 2 1 * 0 Telex: 0 7 9 1 3 7 iiasa a Telefax: (0 2 2 36) 71313

TRANSPORTATION AND

ENERGY SYSTEMS IN THE U.S.

N. Nakicenovic

WP-87-001 January 1987

Working Papers are interim reports on work of the International Institute for Applied Systems Analysis and have received only limited review. Views or opinions expressed herein do not necessarily represent those of the Institute or of its National Member Organizations.

Ffl I IASA

International Institute for Applied Systems Analysis A-2361 Laxenburg O Austria

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Telephone: (0 22 36) 715 21 * O Telex: 079 137 iiasa a Telefax: ( 0 22 36) 71313

PREFACE

This paper was prepared f o r the National Academy of Engineering Workshop on 'The Evaluation of Infrastructures", W o o d s Hole, U.S.A., 11-13 August 1986. It is based on r e s e a r c h conducted together with Arnulf Grubler within the s c o p e of the dynamics of Technology project. of the Technology, Economy, Society Program.

TABLE OF CONTENTS Page

1 INTRODUCTION

2 TRANSPORTATION

2.1 A i r c r a f t 2.2 A u t o m o b i l e 2.3 Railmads 2.4 C a n a l s

2-5 T r a n s p o r t I n f r a s t r u c t u r e s

3 PRIMARY ENERGY

3-1 E n e r g y C o n s u m p t i o n 3.2 E n e r g y S u b s t i t u t i o n

3.3 Oil a n d N a t u r a l G a s P r o d u c t i o n 3.4 Oil a n d G a s T r a n s p o r t

4 CONCLUSIONS

L E T

OF FIGURES Page

F i g u r e 2.1 World A i r T r a n s p o r t

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All O p e r a t i o n s . F i g u r e 2.2 World A i r T r a n s p o r t

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L o g i s t i c P l o t . F i g u r e 2.3 P a s s e n g e r A i r c r a f t P e r f o r m a n c e . F i g u r e 2.4 P e r f o r m a n c e of A i r c r a f t E n g i n e s .

F i g u r e 2.5 N u m b e r of A u t o m o b i l e s a n d R o a d H o r s e s (and Mules) i n US.

F i g u r e 2.6 S u b s t i t u t i o n of H o r s e s b y C a r s , US.

F i g u r e 2.7 All R o a d V e h i c l e s i n U s e , US.

F i g u r e 2.8 Mileage of all R o a d s , US.

F i g u r e 2.9 S u b s t i t u t i o n of U n s u r f a c e d b y S u r f a c e d R o a d s , US.

F i g u r e 2.10 M i l e a g e of S u r f a c e d R o a d s , US.

F i g u r e 2.11 G r o w t h P u l s e i n Main R a i l T r a c k O p e r a t e d , US.

F i g u r e 2.12 S u b s t i t u t i o n of S t e a m b y D i e s e l L o c o m o t i v e s , US.

F i g u r e 2.13 L e n g t h of C a n a l s , US.

F i g u r e 2.14 S u b s t i t u t i o n of T r a n s p o r t I n f r a s t r u c t u r e s , US.

F i g u r e 2.15 I n t e r c i t y P a s s e n g e r T r a f f i c S u b s t i t u t i o n , US.

F i g u r e 3.1 P r i m a r y E n e r g y C o n s u m p t i o n , U.S.

F i g u r e 3.2 P r i m a r y E n e r g y S u b s t i t u t i o n , US.

F i g u r e 3.3 N a t u r a l G a s P r o d u c t i o n f r o m Oil a n d G a s Wells, US.

F i g u r e 3.4 E n e r g y S u b s t i t u t i o n a n d G a s T e c h n o l o g i e s , U.S.

F i g u r e 3.5 C r u d e a n d P r o d u c t s Oil P i p e l i n e s L e n g t h , U.S.

F i g u r e 3.6 N a t u r a l G a s P i p e l i n e L e n g t h , U.S.

Transportation and Energy Systems in t h e U . S.

1 INTRODUCTION

The o b j e c t i v e of t h i s p a p e r i s t o a s s e s s , on t h e b a s i s of a number of indicative examples, t h e time needed t o build new a n d r e p l a c e old t r a n s p o r t a t i o n and e n e r g y systems, a n d t h e i r i n f r a s t r u c t u r e s . Most of t h e examples a r e t a k e n from t h e United S t a t e s , s i n c e t h e United States h a s b e e n o n e of t h e few c o u n t r i e s t o e x p e r i e n c e most of t h e technological c h a n g e s t h a t o c c u r r e d d u r i n g t h e l a s t 200 y e a r s . However, b e c a u s e most of t h e s e technological c h a n g e s were subsequently disseminated t h r o u g h o u t t h e world, t h e examples a l s o i n d i c a t e t h e dynamics of t h e s e p r o c e s s e s elsewhere.

Within t h e s c o p e of t h i s p a p e r , t h e use of t h e t e r m i n f r a s t r u c t u r e i s r a t h e r n a r r o w , r e f e r r i n g only t o t r a n s p o r t a t i o n a n d e n e r g y g r i d s a n d n e t w o r k s , and o t h e r components of t h e s e two systems. These two systems are i n t e r e s t i n g b e c a u s e t h e y played a c r u c i a l r o l e in t h e economic a n d technological development p r o c e s s , a r e v e r y c a p i t a l intensive a n d , in g e n e r a l , h a v e long lifetimes. The analysis of t h e h i s t o r i c a l development of t h e s e two systems will include a q u a n t i t a t i v e d e s c r i p t i o n of p e r f o r m a n c e improvement, t h e g e n e r a l evolution of a p a r t i c u l a r i n f r a s t r u c t u r e , a n d t h e r e p l a c e m e n t of old b y new technologies a n d i n f r a s t r u c t u r e s in t e r m s of t h e i r r e l a t i v e m a r k e t s h a r e s . W e use t h e t e r m p e r f o r m a n c e as a multidimensional c o n c e p t (i.e., as a v e c t o r r a t h e r t h a n a s c a l a r i n d i c a t o r ) a n d , w h e r e a p p r o p r i a t e , m e a s u r e t h e s i z e of a n i n f r a s t r u c t u r e as a function of time.

The f i r s t s e c t i o n d e s c r i b e s t h e evolution of t r a n s p o r t system a n d t h e i r r e l a t e d i n f r a s t r u c t u r e s . The a n a l y s i s starts, somewhat unconventionally, with t h e youngest technologies, a i r c r a f t a n d a i r w a y s , a n d e n d s with t h e o l d e s t t r a n s p o r t networks

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c a n a l s a n d waterways. The s e c o n d s e c t i o n d e s c r i b e s t h e evolution of e n e r g y consumption a n d pipelines as a n example of d e d i c a t e d t r a n s p o r t i n f r a s t r u c t u r e s .

2 TRANSPORTATION

2.1 Aircraft

A i r c r a f t are t h e most s u c c e s s f u l of t h e advanced modes of t r a n s p o r t a t i o n . O t h e r c o n c e p t s of r a p i d t r a n s p o r t s u c h as v e r y high s p e e d t r a i n s h a v e shown some limited s u c c e s s b u t are n o t as universally used as a i r c r a f t . In f a c t , t h e r a p i d expansion of a i r t r a v e l d u r i n g r e c e n t d e c a d e s h a s i t s r o o t s in t h e developments

achieved in aerodynamics and o t h e r sciences many decades ago, and especially in t h e engineering achievements between t h e two World Wars. The DC-3 Airliner i s often given a s t h e example of t h e f i r s t "modern" passenger t r a n s p o r t because in many ways i t denotes t h e beginning of t h e " a i r c r a f t age". The u s e of a i r c r a f t f o r t r a n s p o r t h a s i n c r e a s e d e v e r since and t h e i r performance h a s improved by about two o r d e r s of magnitude. Figure 2.1 shows t h e i n c r e a s e of a i r t r a n s p o r t in t h e world measured in million passenger-kilometers p e r y e a r and r e f e r s t o all c a r r i e r o p e r a t i o n s including those of t h e planned economies. The logistic function has been fitted t o t h e a c t u a l d a t a and i t indicates t h a t t h e inflection point in t h e growth of a i r c a r r i e r o p e r a t i o n s o c c u r r e d about t e n y e a r s a g o (i.e. about 1977). This means t h a t a f t e r a v e r y r a p i d , exponential growth period t h e r e is less than one doubling l e f t until t h e estimated s a t u r a t i o n level i s achieved a f t e r t h e y e a r 2000. The growth r a t e h a s been declining f o r about t e n y e a r s and will continue t o do s o until t h e t o t a l volume of all o p e r a t i o n s levels off a f t e r t h e y e a r 2000 at about a 40 p e r c e n t h i g h e r level than a t p r e s e n t .

Figure 2.2 shows t h e same d a t a and fitted logistic c u r v e transformed as z / ( n z ) , where z denotes t h e actual volume of a l l o p e r a t i o n s in a given y e a r (from Figure 2.1) and K is t h e estimated s a t u r a t i o n level. The d a t a and t h e estimated logistic t r e n d line a r e plotted in Figure 2.2 a s f r a c t i o n a l s h a r e s of t h e s a t u r a t i o n level, f = z / n , which simplifies t h e transformation t o f/(l-j'). Transformed in t h i s way, t h e d a t a a p p e a r t o b e on a s t r a i g h t line, which is t h e estimated logistic function. P e r h a p s t h e most interesting r e s u l t i s t h a t i t took about 30 y e a r s until world a i r t r a n s p o r t r e a c h e d i t s inflection point (i.e. o r a b o u t half of t h e estimated s a t u r a t i o n level) and t h a t within two decades s a t u r a t i o n level would.be r e a c h e d . The c r u c i a l question implied by this r e s u l t i s what will happen a f t e r such a possible s a t u r a t i o n ? Can w e e x p e c t a n o t h e r growth pulse, a decline, o r instability of changing p e r i o d s of growth and decline?

To understand t h e implications of a possible s a t u r a t i o n in world a i r t r a n s p o r t o p e r a t i o n s , i t i s n e c e s s a r y t o look a t t h e t r a n s p o r t system in g e n e r a l , comparing aviation with o t h e r modes of t r a n s p o r t , and t o analyze t h e various components of t h e a i r t r a n s p o r t system itself. The a i r c r a f t , a i r p o r t s and ground s e r v i c e s obviously r e p r e s e n t t h e most important components of t h e a i r t r a n s p o r t i n f r a s t r u c t u r e . Commercial aviation i n f r a s t r u c t u r e i s d i f f e r e n t from t h a t of o t h e r competing t r a n s p o r t systems such a s r o a d s o r railways. Airports a r e distributed and not connected as a r e pipelines o r r o a d s , although a i r c r a f t r e p r e s e n t a n i n f r a s t r u c t u r e of complex elements in t h e same way hospitals o r schools do.

T h e r e a r e a number of possible ways t o d e s c r i b e t h e global f l e e t of commercial a i r t r a n s p o r t and how i t developed. An obvious d e s c r i p t o r of t h e f l e e t would b e t h e number of a i r c r a f t in o p e r a t i o n worldwide. In f a c t , this number i n c r e a s e d from a b o u t 3,000 in t h e 1950s t o almost 10,000 in t h e 1980s. However, during t h e same time t h e performance o r c a r r y i n g c a p a c i t y and speed of a i r c r a f t i n c r e a s e d by a b o u t two o r d e r s of magnitude. Thus, t h e size of t h e f l e e t i s not t h e most important d e s c r i p t o r , since much of t h e t r a f f i c is allocated to t h e most productive a i r c r a f t 1 One general finding of a large number of studies i s that many growth processes follow characteristic Sshaped curves. Logistic function i s one of the most widely applied Sshaped growth curves and i s given by: z / ( n - z ) = e x p ( a t +p), where t i s the independent variable usually representing some unit of time, a and 8 are constants, z i s the actual level of growth achieved, while n-z i s the amount of growth s t i l l t o be achieved before the saturation level n i s reached.

Taking logarithms of both s i d e s g i v e s the l e f t side of the equation t o be expressed a s a linear function of time s o that the secular trend of a logistic growth process appears a s a straight line when plotted in t h i s way. Substituting f = z / n in the equation, expresses the growth process in terms of fractional share f of the asymptotic level n reached, i.e. the equation becomes:

f/(l-f)-exp(at +p).

Figure 2.1 World Air T r a n s p o r t

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All Operations.

o p e r a t i n g between t h e l a r g e h u b - a i r p o r t s while o t h e r a i r c r a f t c o n s t i t u t e t h e f e e d e r a n d d i s t r i b u t i o n system t o d e s t i n a t i o n s with lower t r a f f i c volume. The analogy between e l e c t r i c i t y g r i d s o r r o a d systems i s v e r y close

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l a r g e a i r c r a f t c o r r e s p o n d t o high-voltage transmission lines o r p r i m a r y r o a d s .

Fraction ( F = X 1 0.99

Figure 2.2 World Air T r a n s p o r t

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Logistic P l o t .

F i g u r e 2.3 shows t h e improvement o v e r time of o n e i m p o r t a n t p e r f o r m a n c e i n d i c a t o r f o r commercial p a s s e n g e r a i r c r a f t , i . e . , t h e i n c r e a s e of c a r r y i n g c a p a c i t y a n d s p e e d (often called p r o d u c t i v i t y ) m e a s u r e d in p a s s e n g e r - k i l o m e t e r s p e r h o u r . E a c h point o n t h e g r a p h i n d i c a t e s t h e p e r f o r m a n c e of a given a i r c r a f t when used in commercial o p e r a t i o n s f o r t h e f i r s t time. F o r example, t h e DC-3 w a s i n t r o d u c e d in 1935 with a p e r f o r m a n c e of a b o u t 7,400 p a s s e n g e r - k i l o m e t e r s p e r h o u r (about 21 p a s s e n g e r s at a b o u t 350 km/h) w h e r e a s t h e B747 w a s i n t r o d u c e d i n 1969 with a p e r f o r m a n c e of a b o u t 500,000 p a s s e n g e r - k i l o m e t e r s p e r h o u r (about 500 p a s s e n g e r s at a b o u t 1,000 km/h). The l a r g e s t , c u r r e n t B747s c a n c a r r y almost 700 p a s s e n g e r s a n d are t h e r e f o r e a b o u t 100 times as p r o d u c t i v e as t h e DC-3 50 y e a r s ago. The u p p e r c u r v e r e p r e s e n t s a kind of " p e r f o r m a n c e feasibility" f r o n t i e r f o r p a s s e n g e r a i r c r a f t , s i n c e t h e p e r f o r m a n c e of all commercial a i r t r a n s p o r t s at t h e time t h e y w e r e i n t r o d u c e d i s e i t h e r o n o r below t h e c u r v e . F u r t h e r m o r e , all commercially s u c c e s s f u l long-range a i r c r a f t are o n t h e p e r f o r m a n c e f e a s i b i l i t y c u r v e , while a l l o t h e r p l a n e s l i e below t h e c u r v e . Thus, at a n y given time t h e r e a p p e a r s to b e only o n e a p p r o p r i a t e p r o d u c t i v i t y s p e c i f i c a t i o n f o r long-range p a s s e n g e r planes. S i n c e t h e m o r e r e c e n t jet t r a n s p o r t s all fly at a b o u t t h e same s p e e d , t h e a p p r o p r i a t e design f o r a new, h y p o t h e t i c a l long-range t r a n s p o r t should allow f o r a c a p a c i t y of m o r e t h a n 700 p a s s e n g e r s . According to t h e e s t i m a t e d c u r v e , t h e asymptotic c a p a c i t y of t h e l a r g e s t a i r c r a f t i s a b o u t 1,200 p a s s e n g e r s at subsonic s p e e d (i.e. 1,200 p a s s e n g e r k i l o m e t e r s p e r h o u r o r 200,000 p a s s e n g e r k i l o m e t e r s p e r y e a r ) . Another i n t e r e s t i n g f e a t u r e in F i g u r e 2.3 i s t h a t t h e p r o d u c t i v i t y of all p a s s e n g e r a i r c r a f t i s confined within a r a t h e r n a r r o w b a n d

Fraction ( F = X

Figure 2.3 P a s s e n g e r A i r c r a f t Performance.

between the performance feasibility c u r v e and a "parallel" logistic c u r v e with a lag of about nine y e a r s . This "parallel" logistic c u r v e coincides with t h e growth of t h e world a i r t r a n s p o r t from Figure 2.2.

I t took about 33 y e a r s f o r t h e performance of t h e most productive a i r c r a f t t o i n c r e a s e from about one p e r c e n t of t h e estimated asymptotic performance t o about half t h a t performance (e.g. t h e DC-3 r e p r e s e n t s t h e one-percent achievement and t h e B747 roughly the 50-percent mark). In many ways, t h e achievement of the 5 0 p e r c e n t level r e p r e s e n t s a s t r u c t u r a l change in t h e development of the whole p a s s e n g e r a i r c r a f t industry and airlines. Since w e a r e dealing with S s h a p e d growth (i.e. a logistic c u r v e ) t h e growth p r o c e s s is exponential until t h e inflection point (i.e. t h e 50 p e r c e n t level) is achieved. This means t h a t at the beginning t h e r e a r e many doublings in t h e productivity of a i r c r a f t within periods of only a few y e a r s . However, once t h e inflection point (the 50-percent level) is r e a c h e d , t h e r e i s only 2 years. Due t o the symmetry of the l o g i s t i c function, the same time i s required f o r the increase We call the elapsed time between the one and 50 percent points A t , i.e. in t h i s example A t

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³³

from 50 t o 99 percent of the saturation level.

o n e doubling l e f t until t h e s a t u r a t i o n level i s r e a c h e d . In t h e example from Figure 2.3, t h i s development p h a s e o c c u r r e d in 1 9 6 9 with t h e i n t r o d u c t i o n of t h e B747.

S i n c e t h e B747 could in p r i n c i p l e b e s t r e t c h e d b y a b o u t a f a c t o r of two, i t could a l s o b e t h e long-range a i r c r a f t during t h e n e x t two d e c a d e s . T h e r e a f t e r , a new p h a s e of growth i s c o n c e i v a b l e with e i t h e r l a r g e r o r f a s t e r long-range a i r c r a f t a n d in t h e more d i s t a n t f u t u r e possibly both. B e f o r e t h e inflection point, s t r e t c h i n g d o e s n o t h e l p f o r more t h a n a few y e a r s d u e to r a t h e r f r e q u e n t doublings in p r o d u c t i v i t y s o t h a t principally new solutions are n e c e s s a r y . This a l s o means t h a t a wrong model on t h e m a r k e t c a n b e a c r u c i a l b u t n e v e r t h e l e s s r e v e r s i b l e mistake p r o v i d e d t h a t t h e m a n u f a c t u r e r h a s l a r g e enough r e s o u r c e s a t h i s disposal t o launch a new, improved p e r f o r m a n c e model on t h e m a r k e t a f t e r a few y e a r s . However, a f t e r t h e inflection point t h i s i s no l o n g e r a possible s t r a t e g y s i n c e t h o s e a i r c r a f t t h a t are s u c c e s s f u l c a n b e s t r e t c h e d t o meet t h e m a r k e t demand t h r o u g h s a t u r a t i o n . T h e r e f o r e , toward t h e l a t e 1 9 6 0 s designing new long-range t r a n s p o r t suddenly became r i s k i e r t h a n b e f o r e s i n c e a s e c o n d c h a n c e of launching a new model a f t e r a few y e a r s was n o l o n g e r possible. The B747, f o r example, h a d t h e a p p r o p r i a t e p r o d u c t i v i t y , while two o t h e r c o m p e t i t o r s , t h e DC-10 a n d L l O l l were t o o small. Launching a 700 to 800 p a s s e n g e r a i r c r a f t in t h e n e a r f u t u r e could c o n s t i t u t e a g r e a t r i s k s i n c e a s t r e t c h e d B747 c a n d o t h e same job. A s m a l l e r long-range a i r c r a f t would most likely c o n s t i t u t e a f a i l u r e as well s i n c e i t would fall s h o r t of t h e m a r k e t r e q u i r e m e n t s . The design of a s u p e r s o n i c a i r c r a f t with a c a p a c i t y f o r 300 t o 400 p a s s e n g e r s , o r a h y p e r s o n i c t r a n s p o r t with s a y 200 t o 250 p a s s e n g e r s , may t h e r e f o r e b e a b e t t e r s t r a t e g y f o r t h e f i r s t y e a r s of t h e n e x t c e n t u r y . To some e x t e n t this a l s o e x p l a i n s why Concorde c a n n o t b e a commercial s u c c e s s

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with a c a p a c i t y of 1 0 0 p a s s e n g e r s i t w a s 1 5 0 p a s s e n g e r s s h o r t of being a s e r i o u s c o m p e t i t o r t o t h e B747.

F i g u r e 2.4 shows t h e p e r f o r m a n c e improvement of civil a i r c r a f t engines s i n c e t h e beginning of aviation. The f i r s t piston engine visible on t h e p l o t i s t h e F r e n c h Antoinette engine r a t e d a t 5 0 h p in 1906 a n d t h e l a s t i s t h e American Wright T u r b o Compound r a t e d at 3400 h p in 1950. These r e p r e s e n t a n improvement in power of almost two o r d e r s of magnitude d u r i n g a p e r i o d of 44 y e a r s , a n d a b o u t 90 p e r c e n t of t h e estimated s a t u r a t i o n level f o r piston engines at a b o u t 3800 h p . A p a r a l l e l development in t h e maximal t h r u s t of j e t engines follows with a lag of a b o u t 3 0 y e a r s : s t a r t i n g in 1944 with t h e German J u n k e r s J u n o 004 ( r a t e d at 900 k g ) a n d ending with t h e American P r a t t a n d Whitney JT9D i n t h e e a r l y 1980s with 9 0 p e r c e n t of t h e estimated s a t u r a t i o n level of a b o u t 29000 kg. Both pulses in t h e improvement of a i r c r a f t engines are c h a r a c t e r i z e d with a A t of a b o u t 30 y e a r s . The midpoints of t h e two pulses o c c u r r e d in 1936 a n d 1966 (i.e., t h e r e s p e c t i v e inflection points) a n d coincide with t h e i n t r o d u c t i o n of t h e DC-3 a n d B747. In f a c t , t h e P r a t t a n d Whitney Twin Wasp, i n t r o d u c e d in 1930, became t h e power p l a n t f o r t h e DC-3. I t a l s o s e r v e d as t h e basis-engine f o r s u b s e q u e n t a n d more powerful d e r i v a t i v e s s u c h as t h e Wasp Major i n t r o d u c e d in 1 9 4 5 toward t h e end of t h e a i r c r a f t piston engine era. Thus, c e r t a i n p a r a l l e l s are visible t o t h e dynamics of p a s s e n g e r a i r c r a f t development beyond t h e obvious similarity in t h e time c o n s t a n t (At of a b o u t 3 0 y e a r s ) . Namely, t h o s e engines i n t r o d u c e d slightly b e f o r e t h e inflection point, s u c h as t h e Twin Wasp, a r e " s t r e t c h e d " b y doubling t h e c y l i n d e r rows t o i n c r e a s e t h e power. The Wright T u r b o Compound r e p r e s e n t s t h e l a s t refinement in a i r c r a f t piston e n g i n e s , t h e major additional f e a t u r e being t h a t turbo-charging was u s e d to d e r i v e shaft-power, o t h e r w i s e t h e engine w a s a d i r e c t d e r i v a t i v e from t h e Wright Cyclone s e r i e s introduced in t h e e a r l y 1 9 3 0 s with Cyclone 9 (which originally powered t h e DC-2).

This r e s u l t i n d i c a t e s t h a t t h e time c o n s t a n t f o r t h e development of p a s s e n g e r a i r c r a f t as o n e of t h e most modern t r a n s p o r t a t i o n modes a p p e a r s t o b e a b o u t 3 0 y e a r s . A s mentioned a b o v e , t h e s t a n d a r d i n d u s t r y design e m e r g e d d u r i n g t h e

Fraction ( F

=

X

1900 191 0 1920 1930 1940 1950 1960 1970 1980 1990 2000 A. Griibler. 1986

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_Jets

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Pistons (HP) Max Thrust

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^Kg

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^(K

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3800) (K

=

29,000)

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Figure 2.4 P e r f o r m a n c e of A i r c r a f t Engines.

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d e p r e s s i o n y e a r s (i.e., t h e 1930s). T h i r t y y e a r s l a t e r t h e B747, t h e f i r s t wide-body j e t t o e n t e r s e r v i c e , r e p r e s e n t e d o n e of t h e most significant improvements in commercial t r a n s p o r t a n d i t s p r o d u c t i v i t y r e p r e s e n t e d half of t h e estimated i n d u s t r y s a t u r a t i o n l e v e l t h a t may b e a p p r o a c h e d toward t h e e n d of t h i s c e n t u r y . Thus, within a p e r i o d of 6 0 y e a r s t h e life c y c l e i s completed, from s t a n d a r d i z a t i o n a n d s u b s e q u e n t r a p i d growth c h a r a c t e r i z e d b y numerous improvements, t h r o u g h t h e inflection point when t h e emphasis c h a n g e s t o competition c h a r a c t e r i z e d b y c o s t r e d u c t i o n s a n d rationalization. These c h a r a c t e r i s t i c s of t h e i n d u s t r y , including s t e a d y p e r f o r m a n c e improvement, are well i l l u s t r a t e d by t h e development of t h e B747 line. Next we will i n v e s t i g a t e t h e development of a n o l d e r system t h a t i s a s t r o n g c o m p e t i t o r f o r t h e a i r l i n e s in long-distance p a s s e n g e r t r a n s p o r t

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^{t h e}

automobile.

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2.2 Automobile

A t t h e beginning of t h e c e n t u r y , v e r y few proponents of t h e automobile envisaged t h a t i t would develop and disseminate throughout t h e world s o rapidly during t h e l a s t 100 y e a r s . But t h e f i r s t h o r s e l e s s c a r r i a g e s a l r e a d y posed a n a l t e r n a t i v e t o t h e horse-drawn buggies a n d wagons. A s a commercial and r e c r e a t i o n a l vehicle, t h e motor car o f f e r e d many potential advantages compared t o o t h e r modes of t r a n s p o r t a t i o n , especially o v e r animal-drawn vehicles. P e r h a p s t h e most important advantage was t h e possibility t o i n c r e a s e t h e r a d i u s of local t r a n s p o r t ; being faster t h e automobile allowed many e n t r e p r e n e u r s to expand t h e i r c i r c l e of customers and o f f e r e d a more flexible mode of business and l e i s u r e t r a n s p o r t .

A t t h e beginning t h e r a i l r o a d s were not challenged by t h e automobile, b u t r a t h e r helped t h e i r expansion since t h e y o f f e r e d a n efficient form of long-distance t r a n s p o r t t h a t combined w e l l with t h e use of motor vehicles f o r local, u r b a n and r u r a l r o a d t r a n s p o r t . Within a few decades, however, t h e automobile became a n important form of t r a n s p o r t f o r both local and long-distance p a s s e n g e r t r a v e l in t h e United S t a t e s . Since t h e 1930s up t o t h e p r e s e n t , t h e t o t a l mileage t r a v e l e d by automobiles, and motor vehicles in g e n e r a l , was divided almost equally between r u r a l and u r b a n t r a v e l .

The automobile had a relatively l a t e s t a r t in t h e United S t a t e s compared with European c o u n t r i e s (e.g. France, Germany and t h e United Kingdom). In 1894 f o u r motor vehicles were r e c o r d e d t o b e in use in t h e United S t a t e s . However, t h e expansion of t h e automobile fleet' t h e r e a f t e r was impressive

-

1 6 vehicles were in use in 1896, 90 in 1897, 8,000 in 1900, almost half a million t e n y e a r s l a t e r and more than one million a f t e r a n o t h e r two y e a r s . Thus, both in terms of production and number of vehicles in use, t h e United S t a t e s quickly s u r p a s s e d European c o u n t r i e s .

Figure 2.5 shows t h e r a p i d i n c r e a s e in t h e number of cars used in t h e United S t a t e s . By t h e 1920s m o r e than ten million automobiles were in use on American r o a d s and t h e 100 million mark was s u r p a s s e d in 1970. Figure 2.5 a l s o shows t h a t t h e expansion of t h e automobile f l e e t i s c h a r a c t e r i z e d by two distinct s e c u l a r t r e n d s with a n inflection in t h e 1930s followed by l e s s r a p i d growth r a t e s . Since t h e t w o s e c u l a r t r e n d s of t h e c u r v e a p p e a r to b e roughly l i n e a r on t h e logarithmic scale in Figure 2.5, t h e automobile f l e e t evolved through two exponential p u l s e s . Our working hypothesis i s t h a t t h e two t r e n d s indicate two d i f f e r e n t p h a s e s of dissemination of motor vehicles in t h e United S t a t e s . The f i r s t c h a r a c t e r i z e s t h e substitution of horse-drawn r o a d vehicles, and t h e second t h e a c t u a l growth of r o a d t r a n s p o r t a f t e r o t h e r , animal-drawn vehicles essentially d i s a p p e a r e d from American r o a d s . Only a f t e r t h e completion of this substitution p r o c e s s did t h e automobile emerge a s a n important competitor to t h e r a i l r o a d s f o r t h e long-distance movement of people and goods, and p e r h a p s , a l s o a s a competitor t o u r b a n t r a n s p o r t a t i o n modes, such as t h e tram, subway o r local t r a i n . Thus, t h e f i r s t expansion phase is more r a p i d since i t r e p r e s e n t s a "market takeover", whereas t h e second r e p r e s e n t s t h e a c t u a l growth of t h e r o a d vehicle f l e e t s and t h e i r associated i n f r a s t r u c t u r e s such as highway systems.

Due t o t h e obvious problems associated with t h e lack of h i s t o r i c a l r e c o r d s about t h e e x a c t number of horse-drawn vehicles in t h e United S t a t e s during t h e f i r s t d e c a d e s a f t e r t h e introduction of t h e automobile in 1895, w e c a n only approximately d e s c r i b e t h e assumed substitution of the h o r s e by t h e motor car during t h e f i r s t ,

F i g u r e 2.5 Number of Automobiles a n d Road H o r s e s (and Mules) in US.

m o r e r a p i d , e x p a n s i o n p h a s e of t h e motor vehicle f l e e t s . A s a r o u g h a p p r o x i m a t i o n of t h i s s u b s t i t u t i o n p r o c e s s , w e u s e t h e number of d r a f t animals ( r o a d h o r s e s a n d mules) a n d automobiles given in F i g u r e 2.5. Sometimes h o r s e a n d s a d d l e were used a s a "road vehicle", b u t o f t e n m o r e t h a n o n e h o r s e was u s e d t o pull buggies a n d wagons. City omnibuses r e q u i r e d a b o u t 15 h o r s e s t o b e in u s e t h e whole d a y a n d a s t a g e c o a c h p r o b a b l y e v e n m o r e , s i n c e t h e h o r s e s were r e p l a c e d a t e a c h s t a t i o n . Thus, F i g u r e 2.5 may o v e r e m p h a s i z e t h e number of horse-drawn v e h i c l e s if t h e number of d r a f t animals i s used as a p r o x y f o r t h e number of v e h i c l e s a c t u a l l y in use. On t h e o t h e r hand, w e h a v e n o t included farm work animals in F i g u r e 2.5, although c e r t a i n l y f a r m h o r s e s were a l s o used as a means of t r a n s p o r t , e s p e c i a l l y in t h e r u r a l a r e a s . Thus, t h e d i s a d v a n t a g e of t h i s r o u g h comparison of t h e number of animal-drawn v e h i c l e s a n d motor cars i s t h a t t h e e s t i m a t e s of non-farm h o r s e s a n d mules a r e c e r t a i n l y n o t v e r y a c c u r a t e a n d are unevenly s p a c e d in time. D e s p i t e t h i s d i s a d v a n t a g e , F i g u r e 2.6 i n d i c a t e s t h a t t h e automobile r e p l a c e d h o r s e - a n d mule- drawn r o a d v e h i c l e s d u r i n g a r e l a t i v e l y s h o r t p e r i o d a n d t h a t t h e s u b s t i t u t i o n p r o c e s s p r o c e e d e d along a logistic p a t h . Motor v e h i c l e s a c h i e v e d a o n e - p e r c e n t 3 One g e n e r a l f i n d i n g of a l a r g e number of s t u d i e s i s t h a t s u b s t i t u t i o n o f an old t e c h n o l o g y b y a new one, e x p r e s s e d i n f r a c t i o n a l t e r m s , f o l l o w s c h a r a c t e r i s t i c S s h a p e d c u r v e s . F i s h e r a n d P r y (1971) f o r m u l a t e d a s i m p l e b u t p o w e r f u l model of t e c h n o l o g i c a l s u b s t i t u t i o n b y p o s t u l a t i n g t h a t t h e r e p l a c e m e n t of a n old by a new t e c h n o l o g y p r o c e e d s along t h e l o g i s t i c g r o w t h c u r v e :

f/(l-f ) = e x p ( a t +H), w h e r e t i s t h e i n d e p e n d e n t v a r i a b l e u s u a l l y r e p r e s e n t i n g s o m e u n i t of t i m e , a a n d @ a r e c o n s t a n t s , is t h e f r a c t i o n a l m a r k e t s h a r e of t h e n e w c o m p e t i t o r , w h i l e 1-f i s t h a t of t h e old one.

Figure 2.6 Substitution of H o r s e s by C a r s , US.

s h a r e in r o a d vehicles s h o r t l y a f t e r 1900, a n d a 5 0 p e r c e n t s h a r e in 1917. A complete t a k e o v e r of t h e "market" o c c u r r e d in 1930 with 2 3 million cars o v e r 0 . 3 million r o a d h o r s e s a n d mules c o m p a r e d t o almost two million t e n y e a r s e a r l i e r . This r e s u l t indicates t h a t t h e inflection point of t h e s e c u l a r t r e n d of r e g i s t e r e d c a r s from Figure 2.5 a c t u a l l y coincides with t h e e n d of t h e substitution of animal-drawn r o a d vehicles a n d e x p l a i n s t h e "saturation" in t h e growth of motor vehicles p e r c e i v e d b y many a n a l y s t s d u r i n g t h e l a t e 1 9 2 0 s a n d e a r l y 1930s. This p e r c e i v e d s a t u r a t i o n m a r k s t h e beginning of a new p h a s e in t h e motorization of America, with growth rates c o m p a r a b l e t o t h o s e of t h e expansion of horse-drawn vehicles b e f o r e t h e automobile a g e . S e e n from t h i s p e r s p e c t i v e , t h e growth in t h e number of a l l r o a d v e h i c l e s i s a continuous p r o c e s s o v e r t h e e n t i r e p e r i o d from 1850 t o d a t e . Figure 2.7 shows t h e s e c u l a r i n c r e a s e of a l l r o a d vehicles, horse-drawn a n d motor powered, as a logistic growth p r o c e s s with a n a p p a r e n t s a t u r a t i o n level of a b o u t 350 million vehicles a f t e r t h e y e a r 2030 a n d A t of a b o u t 1 0 0 y e a r s .

Thus, w e are dealing with two simultaneous p r o c e s s e s , t h e growth of r o a d t r a n s p o r t in g e n e r a l a n d t h e substitution of h o r s e c a r r i a g e s a n d wagons by automobiles. Because t h e s e two s e c u l a r developments o v e r l a p in time t h e y t o g e t h e r h a v e t h e e f f e c t of producing two growth t r e n d s in t h e automobile f l e e t with a n inflection point in t h e 1 9 3 0 s marking t h e s t r u c t u r a l c h a n g e in t h e composition of t h e r o a d vehicle f l e e t s , b u t only o n e logistic growth t r e n d f o r a l l r o a d vehicles. Thus, l i k e a i r c r a f t , r o a d v e h i c l e s c o n s t i t u t e a kind of d i s t r i b u t e d i n f r a s t r u c t u r e t h a t e x p a n d s in time as o n e c o n n e c t e d system.

F i g u r e 2.7 A l l Road Vehicles in Use, US.

In f a c t , both a i r a n d r o a d t r a n s p o r t systems r e q u i r e e l a b o r a t e a n d s o p h i s t i c a t e d i n f r a s t r u c t u r e s . P e r h a p s t h e most obvious examples are a i r p o r t s a n d s u p p o r t i n g g r o u n d s y s t e m s f o r a i r c r a f t , a n d r o a d s a n d s e r v i c e i n f r a s t r u c t u r e f o r r o a d vehicles. In t h e c a s e of t r a i n s a n d a i r c r a f t i t i s self e v i d e n t t h a t a i r p o r t s a n d r a i l r o a d s were c o n s t r u c t e d with t h e single p u r p o s e of providing t h e i n f r a s t r u c t u r e f o r t h e s e t r a n s p o r t modes. However, in t h e case of t h e automobile i t i s n o t s o c l e a r w h e t h e r t h e r o a d s p r o v i d e d t h e n i c h e i n t o which t h e m o t o r car e x p a n d e d o r if good r o a d s had to b e d e v e l o p e d b e c a u s e t h e car f l e e t s were expanding. Whether t h e automobile c a u s e d t h e n e e d f o r good r o a d s , o r t h e c o n s t r u c t i o n of good r o a d s c a u s e d t h e development of t h e automobile i n d u s t r y (an a r g u m e n t a l r e a d y d e b a t e d in t h e 1 9 3 0 s , see e.g. E p s t e i n , 1928). t h e e x p a n s i o n of r o a d v e h i c l e f l e e t s i s p a r a l l e l e d b y t h e mileage growth of s u r f a c e d r o a d s , although t h e t o t a l mileage of a l l r o a d s i n c r e a s e d v e r y slowly f r o m 3.16 million miles in 1 9 2 1 t o 3.85 million miles in 1981.

F i g u r e 2.8 shows t h e t o t a l r o a d mileage in t h e United States a n d t h e mileage of u r b a n streets ( e a r l i e r defined as municipal s t r e e t s ) , r u r a l r o a d s a n d a l l u r b a n a n d r u r a l s u r f a c e d r o a d s (bituminous p e n e t r a t i o n , a s p h a l t , c o n c r e t e , wood, s t o n e a n d o t h e r ) . The f i g u r e i l l u s t r a t e s t h a t t h e growth of s u r f a c e d r o a d s p a r a l l e l e d t h e growth of all r o a d v e h i c l e f l e e t s while t h e mileage of a l l r o a d s i n c r e a s e d v e r y slowly. However, t h e e x p a n s i o n of s u r f a c e d r o a d s p r e c e d e d t h e e x p a n s i o n of motor vehicles. In 1 9 0 5 e i g h t p e r c e n t of a l l r o a d s were s u r f a c e d , b u t less t h a n 8 0 thousand m o t o r v e h i c l e s were in u s e c o m p a r e d t o a b o u t 3.3 million r o a d h o r s e s a n d mules (in addition t o t h e 22 million d r a f t animals used f o r farming). Thus, t h e e a r l y s u r f a c e d r o a d s were d e v e l o p e d f o r h o r s e s a n d n o t automobiles, b u t m o t o r v e h i c l e s

1000 fllles

J *t

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3 rural 10

surf aced/

F i g u r e 2.8 Mileage of all Roads, US.

quickly e x p a n d e d i n t o t h e growing i n f r a s t r u c t u r e .

F i g u r e 2.9 shows t h e s u b s t i t u t i o n of u n s u r f a c e d b y s u r f a c e d r o a d s . In 1 9 1 0 a b o u t 1 0 p e r c e n t of a l l r o a d s were s u r f a c e d , d u r i n g t h e 1 9 4 0 s a b o u t o n e h a l f , a n d t o d a y a b o u t 9 0 p e r c e n t are s u r f a c e d , s o t h a t t h e s u b s t i t u t i o n p r o c e s s l a s t e d (i.e. A t i s ) a b o u t 75 y e a r s . T h e r e f o r e , we c a n conclude t h a t t h e i n t r o d u c t i o n of s u r f a c e d r o a d s p r e c e d e d t h e i n t r o d u c t i o n of motor v e h i c l e s in t h e United S t a t e s , b u t t h a t t h e f i r s t rapid-growth p h a s e of motor v e h i c l e f l e e t s o c c u r r e d while l e s s t h a n o n e half of American r o a d s w e r e s u i t a b l e f o r t h e i r use. I t i s a l s o i n t e r e s t i n g to n o t e t h a t t h e s u b s t i t u t i o n p r o c e s s d o e s n o t r e f l e c t t h e vigorous r o a d c o n s t r u c t i o n e f f o r t a f t e r t h e d e p r e s s i o n y e a r s in t h e United S t a t e s , b u t r a t h e r i n d i c a t e s a l a c k of s u c h e f f o r t d u r i n g t h e 1 9 1 0 s a n d 1 9 2 0 s b e c a u s e t h e a c t u a l e x p a n s i o n of s u r f a c e d mileage i s somewhat below t h e long-term t r e n d d u r i n g t h e s e two d e c a d e s . A similar u n d e r e x p a n s i o n o c c u r r e d d u r i n g t h e e a r l y 1 9 7 0 s , b u t a p p e a r s t o h a v e b e e n r e a b s o r b e d d u r i n g t h e l a s t few y e a r s . This i s a r e a s s u r i n g r e s u l t s i n c e i t confirms t h e o b s e r v a t i o n t h a t i n f r a s t r u c t u r e i s a p r e r e q u i s i t e f o r t h e e x p a n s i o n of t r a n s p o r t systems. R a i l r o a d s a n d a i r p o r t s h a d to b e c o n s t r u c t e d f o r t r a i n s a n d a i r c r a f t a n d , in t h e same way, s u r f a c e d r o a d s were r e q u i r e d f o r t h e widespread u s e of motor vehicles. F i g u r e 2.10 shows t h e i n c r e a s e of s u r f a c e d r o a d mileage as a logistic growth p r o c e s s with a s a t u r a t i o n l e v e l of a b o u t 3.5 million miles (almost r e a c h e d with 3.4 million miles t o d a y ) t h a t p a r a l l e l s t h e s u b s t i t u t i o n p r o c e s s of u n s u r f a c e d b y s u r f a c e d r o a d s from F i g u r e 2.9. Thus, s u r f a c e d r o a d s , as a n i m p o r t a n t i n f r a s t r u c t u r e f o r r o a d t r a n s p o r t , a p p e a r to b e in s a t u r a t i o n t o d a y , while t h e automobile f l e e t i s s t i l l growing a n d should r e a c h i t s e s t i m a t e d s a t u r a t i o n p h a s e in a b o u t 5 0 y e a r s .

F i g u r e 2.9 S u b s t i t u t i o n of U n s u r f a c e d b y S u r f a c e d Roads, US.

F i g u r e 2.10 Mileage of S u r f a c e d Roads, US.

2.3 Railroads

W e h a v e s e e n t h a t a i r t r a n s p o r t a n d t h e automobile are s t i l l expanding modes of p a s s e n g e r t r a v e l . R a i l r o a d s , on t h e o t h e r h a n d , are now in t h e p o s t - s a t u r a t i o n development p h a s e . In t e r m s of i n t e r c i t y p a s s e n g e r t r a f f i c in t h e United S t a t e s , t h e i r position vis-a-vie a i r c r a f t a n d t h e automobile i s being e r o d e d . I t i s symbolic of t h i s d e c a y p r o c e s s t h a t t h e t r a n s c o n t i n e n t a l railway s e r v i c e h a s b e e n discontinued in t h e U.S. While widespread a i r t r a v e l i s only a b o u t 5 0 y e a r s old a n d t h e f i r s t automobile p e r h a p s a b o u t 1 0 0 y e a r s , t h e f i r s t r a i l r o a d s of s i g n i f i c a n t length w e r e i n t r o d u c e d 5 0 y e a r s e a r l i e r , o r m o r e t h a n 1 5 0 y e a r s ago. Although r a i l r o a d s were also d e v e l o p e d l a r g e l y in E u r o p e , l i k e t h e automobile t h e y h a d t h e i r most d r a m a t i c growth in t h e United States. By 1840, o r m o r e t h a n t e n y e a r s a f t e r t h e f i r s t commercial l i n e s went i n t o s e r v i c e , t h e United S t a t e s h a d almost 4,500 km of r a i l r o a d c o m p a r e d t o E u r o p e ' s 3 , 0 0 0 km ( s e e Taylor, 1951).

The Baltimore a n d Ohio R a i l r o a d , p r o b a b l y t h e f i r s t commercial r a i l r o a d in t h e United S t a t e s , w a s c h a r t e r e d in 1829; two y e a r s l a t e r i t h a d 13 miles of t r a c k in o p e r a t i o n . Many p r o j e c t s soon followed. In 1833 t h e C h a r l e s t o n a n d Hamburg R a i l r o a d along t h e Savannah R i v e r r o u t e was t h e longest r a i l r o a d in t h e world u n d e r single management with 1 2 6 miles of t r a c k . By 1935, t h r e e Boston r a i l r o a d s w e r e in o p e r a t i o n , o n e t o Lowell, o n e to W o r c e s t e r a n d t h e t h i r d to P r o v i d e n c e .

To a n e x t e n t , t h e e a r l y railway lines were f e e d e r lines f o r c a n a l and waterway t r a n s p o r t systems in much t h e same way as t h e e a r l y commercial motor v e h i c l e s were f o r railways. Tramways (as e a r l y d e d i c a t e d t r a c k s with animal-drawn o r steam t r a i n s were c a l l e d ) in t h e Pennsylvania c o a l fields augmented c a n a l t r a f f i c , and some of t h e f i r s t r a i l r o a d s connecting t o t h e E r i e Canal originally s e r v e d as b r a n c h l i n e s f o r t h a t c a n a l . In f a c t t h e e a r l y r a i l r o a d s w e r e n o t allowed t o compete with t h e E r i e Canal. But e v e n t h e s e e a r l i e s t r a i l r o a d s were l a r g e l y independent t r a n s p o r t a g e n t s and p r o v e d t o b e s t u r d y r i v a l s f o r t h e o l d e r c a n a l s . Thus railways were both f e e d e r lines f o r c a n a l s where t h e y could n o t compete with t h e c a n a l s , b u t a l s o provided a l t e r n a t i v e t r a f f i c r o u t e s , and consequently d i r e c t competition, t o c a n a l s a n d t u r n p i k e s . F o r example, t h e Boston a n d W o r c e s t e r Railway w a s a c o m p e t i t o r of t h e Blackstone Canal, and when completed, t h e P r o v i d e n c e and W o r c e s t e r R a i l r o a d p u t t h i s c a n a l o u t of business. The Baltimore a n d Ohio Railroad took business away from t h e C h e s a p e a k e and Ohio Canal, a n d t h e Charleston a n d Hamburg R a i l r o a d w a s designed t o , a n d did to some e x t e n t , d i v e r t t r a f f i c from t h e lower S a v a n n a h R i v e r . This i s again analogous t o t h e competition between motor v e h i c l e s a n d r a i l r o a d s , a n d t h e e v e n t u a l r e p l a c e m e n t of t r a i n s by motor vehicles in some m a r k e t segments, a n d t h e symbiotic development of e a r l y motor vehicles as a f e e d e r system t o t h e r a i l r o a d network.

S t a r t i n g in t h e 1 8 3 0 s , t h e expansion of t h e r a i l r o a d s in t h e United S t a t e s w a s v e r y r a p i d f o r almost 1 0 0 y e a r s . This growth p r o c e s s i s i l l u s t r a t e d in Figure 2.11, J ~ h i c h shows t h e i n c r e a s e in o p e r a t e d mileage of f i r s t a n d o t h e r main t r a c k s in t h e United S t a t e s s i n c e 1835. The mileage i n c r e a s e d as a single logistic pulse r e a c h i n g s a t u r a t i o n i n 1929 with a At of a b o u t 5 0 y e a r s .

FRRCTION

(F=X/KI

Figure 2.11 Growth P u l s e in Main Rail T r a c k O p e r a t e d , US.

I t declined logistically t h e r e a f t e r with a At of about 125 y e a r s . The i n c r e a s e in t e r m s of t h e a c t u a l length of o p e r a t e d main t r a c k i n f r a s t r u c t u r e , was from about 4,500 km (less t h a n 3,000 mi) in 1840 t o o v e r 480,000 km (about 300,000 mi) in 1929;

about two o r d e r s of magnitude in 90 y e a r s . In comparison, t h e decline w a s a r a t h e r slow process: by t h e 1980s t h e length of main t r a c k actually in o p e r a t i o n d e c r e a s e d by about one t h i r d t o some 320,000 km (about 200,000 mi). Thus, t h e phase of decline (about 50 y e a r s ) a p p e a r s t o b e slower than t h e growth phase probably because o l d e r technologies and i n f r a s t r u c t u r e s e n t e r e d new niches a f t e r t h e s a t u r a t i o n and displacement by new competitors. For example, sailing ships, wood f i r e s and h o r s e riding have all become f a v o r i t e l e i s u r e time and s p o r t i n g activities although in t h e i r original markets were r e p l a c e d by new technologies long ago.

Thus, in t h i s s e n s e t h e railways may e n t e r a new e r a of use although t h e y h a v e virtually lost any significance as a mode of i n t e r c i t y passenger t r a v e l . Local p a s s e n g e r t r a f f i c and t o u r i s t c r u i s e s ( p e r h a p s similar t o ocean c r u i s e s ) may b e a l t e r n a t i v e uses f o r t h i s l a r g e i n f r a s t r u c t u r e in t h e f u t u r e . Some canals a r e a l r e a d y serving such a p u r p o s e although t h e y have not been p r o f i t a b l e a s a means of t r a n s p o r t s i n c e the hay days of r a i l r o a d s . But both c a n a l s and r a i l r o a d s still o f f e r efficient t r a n s p o r t f o r low-value goods ( p e r unit weight a n d / o r volume).

Many technological improvements were introduced in t h e United S t a t e s during t h e f i r s t decades of t h e r a i l r o a d expansion. Most of t h e e a r l y American r a i l r o a d s adopted wooden r a i l s often 20 t o 25 f e e t long capped with a n i r o n s t r a p o r b a r . In 1831 R o b e r t I. Stevens o r d e r e d i r o n T-rails from England and installed them on t h e New J e r s e y Railroad (see Taylor, 1962), b u t i t was not until t h e 1860s t h a t T-rails became a prominent design f e a t u r e on American r a i l r o a d s . In 1847 t h e y became mandatory in t h e s t a t e of New York, although wooden r a i l s were s t i l l in use on t h e western r o u t e s then u n d e r construction. I r o n r a i l s were a significant improvement since t h e y made t h e use of h e a v i e r locomotives and loads possible and t h e r e b y i n c r e a s e d t h e efficiency of r a i l t r a n s p o r t . L a t e r , t h e iron r a i l s were substituted by steel. Thus, t h e basic construction materials in r a i l r o a d i n f r a s t r u c t u r e were shifted from wood t o l a r g e r s h a r e s of initially i r o n and l a t e r s t e e l . A t t h e same time, t h e e n e r g y s o u r c e s a l s o changed from t h e d r a f t animals t h a t were used in t h e f i r s t tramways t o steam locomotives f i r e d by wood, which t h e n remained t h e principal fuel used by r a i l r o a d s until about 1870 ( S h u r r and N a t s c h e r t , 1960). Wood w a s then r e p l a c e d by c o a l and l a t e r steam locomotives in g e n e r a l were r e p l a c e d by diesel ones. Figure 2.12 shows t h e substitution of steam by diesel locomotives. The f i r s t diesel locomotive w a s introduced in 1925 during t h e time when t h e t o t a l number of locomotives peaked a t about 69,000 and a few y e a r s b e f o r e t h e length of main t r a c k in o p e r a t i o n r e a c h e d i t s maximum and s t a r t e d t o decline. Some e l e c t r i c locomotives were introduced e a r l i e r but t h e y n e v e r gained any importance in t h e United S t a t e s and always stayed below a two p e r c e n t s h a r e in t h e t o t a l locomotive f l e e t . The replacement of steam by diesel locomotives w a s a swift p r o c e s s t h a t l a s t e d slightly longer than 20 y e a r s (a l i t t l e s h o r t e r t h a n t h e time taken f o r t h e substitution of h o r s e s by automobiles t h a t lasted less t h a n 30 y e a r s ) . In 1938 diesel locomotives r e a c h e d a one-precent s h a r e in t o t a l locomotives and by t h e 1960s more than a 99 p e r c e n t s h a r e . Thus, while t h e substitution of steam by diesel locomotives was a f a s t technological change in t h e composition of t h e f l e e t , t h e continuous i n c r e a s e in performance of t h e r a i l r o a d t r a n s p o r t system i s c h a r a c t e r i z e d with longer s e c u l a r t r e n d s . Since t h e f i r s t designs a t t h e beginning of t h e l a s t c e n t u r y , t h e t r a c t i o n of locomotives i n c r e a s e d through improvements in t h e efficiency of e n e r g y conversion and subsequent i n c r e a s e of horsepower, and through i n c r e a s e d weight (only possible because of t h e improvements in t r a c k s and materials). In terms of t o t a l installed horsepower of all locomotives, t h e absolute peak was achieved in 1929 with more than 1 0 0 million horsepower of about 60,000 (mostly

FRACTION IF1

F i g u r e 2.12 S u b s t i t u t i o n of Steam b y Diesel Locomotives, US.

s t e a m ) locomotives. This p e a k c o i n c i d e s with t h e maximal l e n g t h of main t r a c k s a l s o a c h i e v e d in 1 9 2 9 . Although t h e t o t a l installed h o r s e p o w e r d e c r e a s e d a f t e r 1 9 2 9 , t h e a v e r a g e t r a c t i v e e f f o r t of a l l locomotives continued to i n c r e a s e t h r o u g h t h e 1 9 7 0 s b e c a u s e t h e t o t a l number of locomotives also declined s i n c e 1925.

A number of o t h e r i n d i c a t o r s of t h e r a i l r o a d system in t h e United States show t h a t t h e 1 9 2 0 s r e p r e s e n t e d t h e culmination of railways. While t h e c a p a c i t y continued t o i n c r e a s e in a n analogous way to t h e t r a c t i v e e f f o r t of locomotives, t h e n u m b e r of p a s s e n g e r - t r a i n c a r s in s e r v i c e p e a k e d in 1924 at more t h a n 5 7 , 0 0 0 a n d f r e i g h t - t r a i n c a r s in s e r v i c e p e a k e d in 1 9 2 5 at m o r e t h a n 2.4 million. The number of p a s s e n g e r s c a r r i e d a n d passenger-miles also p e a k e d d u r i n g t h e same d e c a d e ( p a s s e n g e r s a t o v e r 1 . 2 billion a n d passenger-miles at m o r e t h a n 4 7 billion b o t h in 1920). All of t h e s e i n d i c a t o r s d e c l i n e d s u b s e q u e n t l y to somewhere between 3 0 a n d 40 p e r c e n t of t h e maximal v a l u e s r e a c h e d d u r i n g t h e 1920s.

A c e r t a i n p a r a l l e l in t h e development of r a i l r o a d s a n d automobiles c a n b e d e t e c t e d . I n a m o r e s u p e r f i c i a l way b o t h systems imitated t h e design of t h e t r a n s p o r t modes t h a t t h e y w e r e competing with a n d e v e n t u a l l y s u b s t i t u t e d . F i r s t motor v e h i c l e s w e r e l i t e r a l l y horseLess c a r r i a g e s : t h e y w e r e almost i d e n t i c a l e x c e p t f o r t h e d i f f e r e n c e in t h e prime mover. Analogously, e a r l y r a i l r o a d p a s s e n g e r c a r s w e r e i d e n t i c a l to s t a g e c o a c h e s both in design a n d a p p e a r a n c e . More fundamentally, in t h e United S t a t e s t h e e x p a n s i o n of main t r a c k w a s only s l i g h t l y f a s t e r t h a n t h e e x p a n s i o n of s u r f a c e d r o a d s . Both growth p r o c e s s e s a r e c h a r a c t e r i z e d with a At of r o u g h l y 5 0 y e a r s (i.e. r a i l r o a d s of a b o u t 4 7 a n d r o a d s

a b o u t 5 5 ) , b u t a r e s e p a r a t e d in time b y a b o u t 5 0 y e a r s . The inflection points of t h e t w o growth pulses a r e s e p a r a t e d b y 5 6 y e a r s ; t h e main t r a c k s r e a c h e d half t h e s a t u r a t i o n l e v e l in 1890 a n d s u r f a c e d r o a d s in 1946. Thus, t h e growth of t h e s e two i n f r a s t r u c t u r e s is c h a r a c t e r i z e d b y a "time c o n s t a n t " of a b o u t 5 0 y e a r s , while t h e d e c l i n e of r a i l r o a d i n f r a s t r u c t u r e a p p e a r s to b e a s l o w e r p r o c e s s . Another fundamental similarity in t h e evolution of t h e two t r a n s p o r t a t i o n systems i s t h a t important c h a n g e s in r o a d t r a n s p o r t o c c u r r e d d u r i n g t h e y e a r s when most p e r f o r m a n c e i n d i c a t o r s of railways w e r e s a t u r a t i n g . Railways s a t u r a t e d d u r i n g t h e 1 9 2 0 s and d u r i n g t h e same d e c a d e t h e s u b s t i t u t i o n of h o r s e s b y automobiles w a s completed. O t h e r fundamental innovations w e r e a l s o i n t r o d u c e d in t h e r a p i d l y expanding automotive i n d u s t r y d u r i n g t h i s p e r i o d s u c h as mass p r o d u c t i o n a n d c l o s e d car bodies. Thus, while t h e r a i l r o a d s w e r e s a t u r a t i n g , t h e automobile i n d u s t r y m a t u r e d a n d i n t r o d u c e d i m p o r t a n t c h a n g e s t h a t g e n e r a t e d s u b s e q u e n t growth.

Tt i s useful t h e r e f o r e to distinguish t w o d i f f e r e n t a s p e c t s in t h e evolution of t h e t w o t r a n s p o r t i n f r a s t r u c t u r e s . While t h e growth of main t r a c k s a n d s u r f a c e d r o a d s l a s t e d on t h e o r d e r of 5 0 y e a r s , t h e technological c h a n g e s a n d slibstitution of old b y new equipment i s a much f a s t e r p r o c e s s of a b o u t 1 0 to 20 y e a r s at t h e l e v e l of locomotive or automotive f l e e t s . These p r o c e s s e s continue e v e n a f t e r t h e s a t u r a t i o n p h a s e i s r e a c h e d as t h e s u b s t i t u t i o n of steam b y d i e s e l locomotives indicated. Thus, technological c h a n g e s are i m p o r t a n t in b o t h growing a n d declining i n d u s t r i e s . Tn growing i n d u s t r i e s new technologies are i n t r o d u c e d t h r o u g h new additions a n d r e p l a c e m e n t , while in t h e declining i n d u s t r i e s new t e c h n o l o g i e s are i n t r o d u c e d exclusively t h r o u g h p a r t i a l r e p l a c e m e n t of old technologies.

2.4 Canals

I t a p p e a r s t h a t t h e evolution of r a i l a n d r o a d t r a n s p o r t s y s t e m s p o r t r a y s similar f e a t u r e s a n d time c o n s t a n t s ( A t ) in t h e i r p e r f o r m a n c e improvement, technological s n b s t i t u t i o n , a n d i n t h e i n c r e a s e in t h e s i z e of t h e i r s u p p o r t i n g i n f r a s t r u c t u r e s . The i m p o r t a n t e v e n t s in t h e evolution of t h e t w o s y s t e m s , h o w e v e r , a r e d i s p l a c e d in time b y a b o u t 5 0 y e a r s . R a i l r o a d s s a t u r a t e d d u r i n g t h e 1 9 2 0 s when some of t h e most i m p o r t a n t technological c h a n g e s and improvements in r o a d t r a n s p o r t were initiated. Thus, t h i s similarity i s p e r h a p s i n d i c a t i v e of a n i n v a r i a n c e in t h e development p a t t e r n of t r a n s p o r t systems a n d t h e i r underlying i n f r a s t r u c t u r e s . A s e r i o u s problem a r i s e s , however, when comparing t h e s e t w o t r a n s p o r t a t i o n modes with t h o s e t h a t d o n o t d e p e n d exclusively o n t h e r i g i d , man- made links between them. Airways a n d waterways a r e e x a m p l e s of t r a n s p o r t s y s t e m s t h a t r e l y l e s s on t h e man-made links between t h e nodes b e c a u s e t h e y u s e t h e n a t u r a l environment (i.e. a i r , r i v e r s a n d c o a s t a l w a t e r s ) b u t n e v e r t h e l e s s r e q u i r e a n e l a b o r a t e i n f r a s t r u c t u r e s u c h as a i r p o r t s , h a r b o r s a n d c a n a l s . Consequently, i t is difficult to a s s e s s t h e t o t a l length of t h e implicit a i r a n d waterway r o u t e s t h a t would b e equivalent to t h e length of main r a i l r o a d t r a c k s o r s u r f a c e d r o a d s . In both c a s e s , h o w e v e r , t h e r e are a b s t r a c t c o n c e p t s t h a t would, in p r i n c i p l e , c o r r e s p o n d to t h e length of t h e g r i d : t h e network of c e r t i f i e d r o u t e c a r r i e r s o r f e d e r a l a i r w a y s in a i r t r a n s p o r t , and t h e t o t a l length of c o n t i n e n t a l l ~ a t e r w a y s a n d c a n a l s . U n f o r t u n a t e l y , t h e a n n u a l i n c r e a s e in a c t u a l o p e r a t e d mileage l e n g t h of a l l a i r c a r r i e r r o u t e s and t h e mileage of used c o n t i n e n t a l waterways a n d c a n a l s is not v e r y a c c u r a t e l y documented in h i s t o r i c a l r e c o r d s . Thus, h e r e w e c a n r e l y only on s p a r s e a c c o u n t s a n d p r o b a b l y i n a c c u r a t e e s t i m a t e s .

The f i r s t d e c a d e s of t h e 1 9 t h c e n t u r y in t h e United S t a t e s m a r k e d t h e beginning of l a r g e r o a d s , c a n a l s , tramways a n d l a t e r railway c o n s t r u c t i o n p r o j e c t s . The y e a r s from a b o u t 1 8 0 0 to 1 8 3 0 h a v e b e e n c a l l e d t h e " t u r n p i k e era" b e c a u s e d u r i n g t h i s p e r i o d a number of t h e r o a d s designed f o r t r a v e l between t h e l a r g e r towns o r to t h e w e s t a c r o s s t h e mountains were completed. T u r n p i k e s , h o w e v e r , were a l r e a d y being abandoned d u r i n g t h e 1 8 2 0 s b e c a u s e of a l a c k of financial s u c c e s s ( s e e T a y l o r , 1962). During t h e s a m e p e r i o d a t t e n t i o n w a s given to c a n a l c o n s t r u c t i o n in a n a t t e m p t t o develop a m o r e e f f e c t i v e means of i n t e r n a l t r a n s p o r t a t i o n t o complement c o a s t a l m e r c h a n t t r a n s p o r t . t o c a n a l c o n s t r u c t i o n while t h e c o n s t r u c t i o n of t u r n p i k e s declined. The "canal era" l a s t e d until t h e railways became t h e main mode of long-distance t r a n s p o r t a few d e c a d e s l a t e r . From t h i s point of view, t h e 1 8 3 0 s were v e r y t u r b u l e n t y e a r s : many t u r n p i k e s were a b a n d o n e d , c a n a l c o n s t r u c t i o n w a s r e a c h i n g i t s p e a k , a n d some e a r l y railway p r o j e c t s were a l r e a d y completed. Thus, s i n c e t h e 1 8 3 0 s t h e r e h a v e b e e n at l e a s t t h r e e d i f f e r e n t t r a n s p o r t modes t h a t t o some e x t e n t p r o v i d e d complementary s e r v i c e s b u t w e r e a l s o competing d i r e c t l y in many m a r k e t segments. In c o n t r a s t t o t u r n p i k e s a n d r a i l w a y s , c a n a l s c o n n e c t e d t h e v a r i o u s n a t u r a l links of t h e inland waterway system a n d did n o t r e p r e s e n t a t r a n s p o r t i n f r a s t r u c t u r e in themselves. I n s t e a d , t h e y are r a t h e r c o m p a r a b l e t o b r i d g e s a n d tunnels as t h e connecting links of r o a d o r r a i l t r a n s p o r t n e t w o r k s . Thus, c a n a l s made t h e inland waterways i n t o a n i n t e g r a t e d t r a n s p o r t system b y connecting t h e l a k e s in t h e n o r t h with t h e r i v e r s in t h e s o u t h - e a s t a n d mid-west.

However, t h e g r e a t waterway a c r o s s t h e United States n e v e r materialized.

The f i r s t c a n a l s were b u i l t d u r i n g t h e 1 7 8 0 s a n d t h e Richmond Falls was t h e f i r s t c a n a l t o e x c e e d a l e n g t h of 7 miles when completed in 1793. From t h e n o n t h e p a c e of c a n a l c o n s t r u c t i o n a c c e l e r a t e d : b y 1 8 0 0 t h e t o t a l l e n g t h of c a n a l s e x c e e d d 5 0 miles a n d by 1 8 2 5 m o r e t h a n 1 , 0 0 0 miles w e r e in o p e r a t i o n . Rapid c o n s t r u c t i o n continued f o r a n o t h e r 20 y e a r s o r s o , r e a c h i n g 3.600 miles in 1850 a n d leveling off at a b o u t 4,000 miles 20 y e a r s l a t e r . T h e r e a f t e r t h e c a n a l b u s i n e s s was s o s e r i o u s l y e r o d e d b y competition from t h e r a i l r o a d s t h a t many i m p o r t a n t c a n a l s were decommissioned. S u b s e q u e n t l y , t h e l e n g t h of a l l c a n a l s in u s e p r o c e e d e d t o d e c l i n e . In t h e United S t a t e s , t h e r i s e a n d f a l l of o p e r a t e d c a n a l s p a r a l l e l s t h e growth a n d d e c l i n e of t h e main railway t r a c k s b u t i s d i s p l a c e d in time b y a b o u t 5 0 y e a r s . In both c a s e s t h e growth in mileage of t h e o p e r a t e d i n f r a s t r u c t u r e i n c r e a s e d r a p i d l y , b u t a f t e r s a t u r a t i o n t h e decline w a s l e s s r a p i d b y f a r .

F i g u r e 2.13 shows t h e i n c r e a s e in t h e length of c a n a l s in t h e United States as a logistic growth pulse with a s a t u r a t i o n l e v e l of a b o u t 4,000 miles a f t e r t h e 1 8 6 0 s . The inflection point, o r t h e maximum rate of g r o w t h , w a s r e a c h e d i n 1835 a n d t h e At i s a b o u t 3 0 y e a r s . Thus, c a n a l s h a v e a time c o n s t a n t c o m p a r a b l e t o t h a t of t h e a i r w a y s b u t s h o r t e r t h a n railways a n d r o a d s . A possible e x p l a n a t i o n f o r t h i s d i f f e r e n c e i s t h a t b o t h c a n a l s a n d a i r w a y s r e p r e s e n t only o n e i m p o r t a n t component of t h e i r a c t u a l i n f r a s t r u c t u r e s , which f o r t h e f o r m e r includes all waterways in addition t o some man-made c a n a l s , a n d f o r t h e latter a l a r g e i n f r a s t r u c t u r e of s u p p o r t i n g systems. On t h e o t h e r h a n d , r a i l r o a d s a n d s u r f a c e d r o a d s in t h e m s e l v e s c o n s t i t u t e a l a r g e c o n n e c t e d i n f r a s t r u c t u r e t h a t i s e s s e n t i a l l y a l l built f o r a s p e c i f i c p u r p o s e , w h e r e a s t o a l a r g e e x t e n t t h e w a t e r a n d a i r w a y s utilize t h e n a t u r a l environment with additional s u p p o r t i n g i n f r a s t r u c t u r e s . Thus, t h i s r e s u l t may simply i l l u s t r a t e t h a t i t t a k e s l o n g e r t o c o n s t r u c t l a r g e i n f r a s t r u c t u r e s s u c h as r o a d s a n d t r a c k s c o m p a r e d with c o n s t r u c t i n g s e l e c t e d links ( c a n a l s o r m o r e a b s t r a c t l y a i r c o r r i d o r s ) a n d nodes ( a i r p o r t s a n d h a r b o r s ) in o r d e r t o e x p a n d a new t r a n s p o r t system s u c h as water a n d a i r w a y s i n t o a n a l r e a d y a v a i l a b l e n a t u r a l environment.