In most more developed cities, private passenger vehicles are the backbone of motorised passenger transport systems and will remain so for the foreseeable future. Although in many cities the city’s public transport networks are in decline, which encourages private motorised mobility, public transport networks comprising buses, trains, trams and ferries still offer an important and viable alternative transportation mode-choice (WBCSD, 2001). In many more developed cities there is a revitalisation of urban public transport systems, especially rail networks, through construction of new lines, remodelling and modernising of stations and stops (USDoT, 1993). Kitamura et al. (1994) and Cervero (1996) describe the ease of access to rail infrastructure and services as being strongly associated with the level of rail patronage and Parsons et al. (1996) note the positive influence of residential development near to rail lines on urban rail usage. Both these groups of researchers suggest these influences draw commuters to urban rail services and away from automobile usage for their daily mobility needs. Kenworthy and Laube (1999) show that American cities have high private motorised mobility and generally low transit service levels and use. In contrast, Schafer (1998) notes that within and between a majority of European cities there is a viable and efficient urban rail network with a high usage demand.
In most cities in the developing world, non-automobile travel is by bus, para-transit modes such as jeepneys and shared taxis, walking, bicycling and other non-motorised modes (such as becaks in Indonesia). Even in cities where suburban rail is predominant (such as Mumbai), and where metros exist, it is still probable that most mechanised journeys are by bus (Cracknell, 2000). However, in many developing cities, urban rail becomes particularly important when high-density urban development expands to create distances that are too great for efficient bus transport. Once this point is reached, road building alone cannot efficiently serve travel demand and a high- capacity integrated public transport network, such as LRT or MTR, is essential for securing mobility and sustainability of urban public transport systems (World Bank, 2000d).
Figure 2.27 shows the relationship between metropolitan urban rail network length (rail metres per capita) and automobiles per 1,000 persons for 1990 and 1995 in a selection of 32 more developed and less developed cities for which data were readily available. In this part metropolitan rail network length comprises a total of the following:
• For 1990 - heavy rail, light rail and tramway (Kenworthy et al., 1999:650).
Figure 2.27 – Metropolitan urban rail network length (rail m/capita) and automobiles per 1,000 persons for a selection of more developed and less developed cities for 1990 and 1995
Note: The 1990 and 1995 data sets have an optimised R2 of 0.194 and 0.333 respectively and are statistically significant
at the ≤0.05 level.
Source: Beyer (1974), Kenworthy et al. (1999), Kenworthy and Laube (2001).
Figure 2.28 shows the relationship between metropolitan urban rail network length per capita and automobile VKT per capita for 1990 and 1995 in the same selection cities.
0.0 100.0 200.0 300.0 400.0 500.0 600.0 700.0 800.0 0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700
Metropolitan urban rail network length (rail metres per capita)
Autom obi le s pe r 1, 000 pe rs ons 1990 1995 1990 1995
Figure 2.28 – Metropolitan urban rail network length (rail m/capita) and automobile VKT/capita for a selection of more developed and less developed cities for 1990 and 1995
Note: The 1990 and 1995 data sets have an optimised R2 of 0.096 and 0.158 respectively and are not and are statistically
significant at the ≤0.05 level respectively.
Source: Beyer (1974), Kenworthy et al. (1999), Kenworthy and Laube (2001).
The lines of best fit are power curves in Figure 2.27 and Figure 2.28 that show, while not statistically significant at the 0.05% level, an increasing positive trend from 1990 to 1995 in the relationship between rail metres per capita and automobile ownership and use. The increasing pace of motorisation and saturation of the road networks, as noted previously, may be contributing to this dampening of automobile ownership in cities with more rail infrastructure. In cities with well established rail networks such as London, Paris, Tokyo and Melbourne the impact on the relationship with automobile ownership was still not significant at the 0.05% level.
In summary, this section suggests that road metres per capita is a measure that drives private motorised mobility at the national and city level, but that it does not act alone as a sole driver. A notable factor here is metropolitan population density as a strong influence on road metres per capita. Although freeway and express road networks are seen as premium road infrastructure, both have a strong linear relationship with automobile ownership and use. As well, indications are that there were historical trends in the relationship across the period investigated and that the relationship was consistent in a selection of more developed and less developed countries and cities. The influence of rail metres per capita on private motorised mobility was overall less well
0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700
Metropolitan urban rail network length (rail metres per capita)
Automobile VKT per capita
1990 1995
1990
defined or clear-cut. This may be attributed in this instance to the data availability and in particular the fact that they were separated by five-years, 1990 and 1995. However, at an individual city level the proximity of rail infrastructure to residential development was a factor in fostering increased rail usage.
2.5.6
Automobile occupancy: an influence on private motorised mobility
This section examines a phenomenon relevant at both the city and household levels: decline in automobile occupancy at the same time that significant increases in both automobile ownership and use have occurred. A decline in automobile occupancy has occurred in both more developed and less developed cities over several decades, from the 1960s to 1990s.