Others argue for the government using some dollars to create subway and train lines in order to reduce street congestion. On the other side of the road are those who think that more and wider roads solve traffic problems best. Write for and against each viewpoint:
Others argue for the government using some dollars to create subway and train lines in order to reduce street congestion. On the other side of the road are those who think that more and wider roads solve traffic problems best. Write for and against each viewpoint:
Urban traffic congestion has become one of the most expensive and polluted characteristics of fast-growing cities around the world, thus increasing pressures on governments to find sustainable solutions. Whether cities invest in more public transit infrastructure — subways and rail networks — or increase road capacity is a remarkably important decision about what the model of urban mobility that they want to see, having immense impacts on their long-term livability, sustainability and economic vitality. After weighing both arguments very carefully, my firm conviction is that development of subway and train networks is a smaller but far more effective approach to the urban congestion crisis than building new roads.
I think this puzzle can – or will one day – be solved, because the case for building both more and larger roads rests on an intuitive logic which goes directly to the observable cause of congestion: roadspace is at less than optimal proportion to vehicle count. If the roads are narrow or too few in number for the traffic they serve, then the most straightforward solution to that capacity deficit seems to be widening those roads or building new ones. Road infrastructure provides greater function across a broader variety of vehicles and journey purpose than rail — due to access for freight movement, emergency vehicle access and the point-to-point nature of most private travel which fixed locations cannot offer with comparable flexibility. In places where population density is not great enough to find the capital investment that rail infrastructure would involve over its lifetime, road improvement might well be the more economically productive mobility investment.
In addition, road construction is a gradually implementable and adaptable solution to demands on transport infrastructure in individual localities — problems that underground rail, once it is committed, will be effectively immovable and very expensive to relocate. In fast-growing cities, where land use patterns are yet to be established and travel demand rarely remains in the same area as development expands or population density evolves, the case for flexibility is compelling.
The only fundamental problem with the road expansion approach to congestion is what transport planners and economists refer to as induced demand — one of the most robustly demonstrated phenomena in transportation research. Road expansion serves as a temporary relief valve for congestion: when road capacity is expanded traffic volume grows to fill the new space — often within months — because drivers who previously avoided trips or timed their journeys to avoid congestion now find their roads empty just long enough to change their travel behaviour. The extra capacity also induces land uses and settlement patterns (and deployments of businesses), that generate additional vehicle trips thereby providing a self-reinforcing wheel of expansion and demand growth making road-building a treadmill instead of a solution. Decades of empirical research — from Los Angeles to Beijing – has shown that cities seeking to alleviate congestion through road expansion largely face worsening problems as new capacity spawns more demand.
The argument for investment in subways and trains relies on a completely different logic. ANALYTICAL INTERLYKH Rail systems represent a further shift in the underlying mode of transport, not just maximizing capacity within the existing urban corridor but making it possible to move far more people through that same corridor—the common interchange point—while using only a fraction of the land[1] and having an order-of-fractions lower per-passenger environmental impact. Cities more broadly with substantial urban rail networks — Tokyo, Singapore, Hong Kong, London — demonstrate time and again that the combination of comprehensive (but frequent) reliable transit can draw enough ridership to significantly mitigate car dependency, moderate traffic volumes and improve overall urban mobility results in ways that road expansion will never deliver.
Rail investments influences urban development patterns that through transit-orientation increase their mobility benefits over time; in particular, developing walkable/mixed-use/intermodal communities around stations create more transportation-energy-efficient growth patterns (fewer vehicle trips per resident) than would dispersed car-dependent suburbs, and therefore further progressively reduce the aggregate demand for travel that congestion is a response to. The environmental benefits — substantially lower per-passenger carbon emissions, less air and noise pollution — only further enhance the case for rail investment as cities experience pressure to reduce their climate change contributions, making rail investment simultaneously aligned with multiple policy objectives.
The investment cost of rail infrastructure is considerable and, especially in developing economies where governments have limited fiscal capacity to invest — that these are be a serious challenge. Nonetheless, the long-term economic returns from the lowering of congestion costs, improved accessibility of workforces and productivity gains at transit-accessible corridors generally justify this cost when values over an appropriate evaluation period.
To summarize, although road widening provides some temporary relief and does have valid use cases in certain low density environments, the evidence is overwhelmingly clear that long-term solutions to urban traffic congestion will be based on subway and train investment. Cities that invest in rail construct mobility systems with decades of compounded benefits; cities that pour money into roads gain at best temporary relief, and generate the very demand growth the infrastructure was ostensibly built to relieve.