Contrary to popular opinion, elevated corridors are not the way out of the congested roads and jammed bottlenecks of either the national capital, or any other city plagued with traffic woes. DNA tells you why
Elevated corridors will not help decongest jammed roads in cities plagued with traffic woes. DNA tells you why
Escalating air pollution levels, crumbling public infrastructure, inefficiency in essential services and the extraordinary manhours expended in simply moving from A to B are some of the societal costs of heavy road congestion. Delhi is no exception to this.
An IIT Madras study in 2017 estimated that congestion costs due to pollution and productivity losses amounted to Rs 54,000 crore in Delhi in 2013 alone. Prerna Vijay Mehta, Lead, Urban Development at the World Resources Institute India, said that on an average, Delhi traffic moves at 45 per cent of road design speed. Road speeds hover at around 5 kilometres per hour during peak hour, which is about the same as walking speed. Unfortunately, the number of vehicles has been rising at an alarming rate.
Delhi alone adds more vehicles on a daily basis than Mumbai, Kolkata and Chennai combined, resulting in choked roads all over the city. Given prevailing conditions, Mehta urges a “logical increase in the number of vehicles”.
To reduce congestion, the Delhi government has proposed an Elevated Corridor along the Mehrauli — Badarpur stretch, which would provide both additional road space for vehicular traffic as well as new Metro connectivity for commuters. This is presently in the approval stage, and similar projects have been proposed in other parts of the city. Prima facie this may appear to be an attractive option, but are elevated corridors truly the right instrument to decongest the city?
Professor Sewa Ram at the School of Planning and Architecture’s Department of Transport Planning, finds that public transport has not managed to keep pace with the expansion of the city and demand is “being met by private transport whose carrying capacity in terms of passenger per hour is lower. This has resulted in pressure on the road based system and thereby, all the roads are operating at crush load.”
For example, the Gurugram expressway is functioning at one and a half times its maximum design capacity. Buses too, are inadequate to meet passenger demand. Incidentally, some of the corridors of metro services are often filled beyond capacity at the initial station itself.
Dr OP Agarwal, CEO of World Resources Institute India and author of the National Urban Transport Policy, pointed out that “affordability has been the prime concern in public transport in India and this has meant that other issues have taken a back seat. Although, this approach may have been appropriate at the time to meet the needs of economically weaker sections”, a lack of comfort in public transport acts as a deterrent to those who can afford alternative means.
According to Mehta, urban car culture also plays a role in driving congestion. Even though cars are viewed as aspirational, they tend to be driven daily to places such as local markets, which could ordinarily be visited on foot. She attributes this to a decline in a sense of community and deterioration of pedestrian infrastructure.
Traffic as a gas
In the 1960s, economist Anthony Downs studied the effect of additional road space on highway congestion in his ‘Law of Peak Hour Expressway Congestion’. Simply stated, he theorised that congestion would rise to meet maximum available capacity. This phenomenon is sometimes referred to as ‘Generated Demand’ and had been observed as early as the 1930s in developed countries. The addition of road space leads to a lowering of ‘costs’ to drive along this route, resulting in an increase in demand and thus, any gains will be short-lived before reverting to a state of heavy congestion.
Ram too stated that, “As more cars enter a stream of traffic, driving speeds reduce and this leads to congestion. To address this, authorities intervene and provide additional road space as in the case of the elevated corridor. Cars would then be able to travel faster only for some time, and then again into enter into cycle of congestion.”
Mehta concurs that traffic expands much like a gas and occupies any space that becomes available to it, suggesting that “trying to fix congestion by building more roads is like trying to reduce obesity by wearing bigger clothes”.
Agarwal argues that the placement of the corridor is itself problematic. Mehrauli, being an entry point to South Delhi, will likely invite more traffic from the surrounding areas adding to the traffic burden, “… which the city’s remaining public road system is incapable of servicing”. He adds that a convenient rule of thumb is that roads should occupy 12-15 per cent of the geographical area of a city. On exceeding this range, there is “usually a much stronger case for encouraging the use of public transport rather than private vehicles”. A December 2018 report by United Resident Joint Action (URJA) and Institute of Urban Designers, Delhi, places this figure at 22 per cent, which is the highest in the country.
If such infrastructure is to be built, Agarwal recommends that it could be more suitably placed beyond Badarpur and would be “more effective in reducing the inflow of traffic from surrounding areas not destined for Delhi”. Professor Ram suggests that there may be some merit to placing the elevated corridor in carefully selected sections along alternative routes such as Ashram to Dhaula Kuan.
Higher demand to drive leads to a higher demand for parking services. Since each new vehicle occupies on average three dedicated parking spaces — one each at home, at the office and in market areas, Mehta calls for a deeper analysis of “road geometrics”
and a broader urban planning perspective in designing road related infrastructure. Agarwal adds that the average private vehicle is parked for 95 per cent of the time, leading to shortages of public road space and adding to congestion along roadways. Since Delhi has one vehicle for every two residents, and this is expected to only worsen, alternatives need to be pursued to prevent such permanent deadlock of the streets.
Due to the presence of illegal construction, road expansion is not always feasible. This is especially true for the Mehrauli — Badarpur route, and has prompted authorities to expand vertically. It is also true that elevated systems do present some cost advantages and a relatively painless way to add to existing road area.
However, as per Ram, “a clear definition of the objectives of the corridor must be established and the capacity must be defined in terms of passenger carrying capacity instead of vehicle carrying capacity”. Even so, the benefits of additional road space in curbing congestion will be short lived and revert to what Benjamin Schneider calls a “selflimiting equilibrium”. However, there are some cases where this has not shown any benefits at all due to vehicles indiscriminately
switching between junctions using the elevated corridor.
Citing the case of NH48, Ram remarked that “it has failed to improve the congestion situation by not accounting for existing motorway traffic appropriately”. Aditi Veena, an urban ecologist and architect added that the DND flyover is a prime example of failure of road capacity to improve congestion. Although drivers maintain a relatively high speed on the DND, heavy congestion remains a perpetual feature at both entry and exit points.
Supporting both Metro and private transport in this project seems “paradoxical” to Mehta, and “communicates a mixed signal to commuters”, by incentivising private vehicles and thus, deterring the use of public transport. In her view, public agencies “are yet to prioritise their objectives” and should avoid construction of “an engineering marvel”, which would prove selfcontradictory.
Ram suggested the extension of this idea to a 3-tier system supporting private vehicles at the lowest level, with additional tiers for Metro lines and bus traffic in selected portions. In this way there will be “double priority” given to public transport along with unavoidable road based systems, since “it is not possible to meet complete demand only by Metro or by road based systems.”
Agarwal suggests that city transport systems should be organised keeping in view that the “maximum number of commuters should move in the least number of vehicles”.
A thirty-seat bus occupies approximately 1m square road space per passenger. On the other hand, a personal vehicle often ferries only a single passenger but would occupy approximately 3m square. It is clear how this contributes to congestion. It is essential that Delhi and other major cities begin re-orienting themselves by encouraging public transport, non-motorised transport and greater pedestrian mobility. The elevated corridor’s primary effects would be unable to deliver on any of these counts.
Most of the Delhi metro and Mumbai has a twin-track system, which can support more trains and would prove more agreeable to an expansion of services. He strongly advocates for “rationalising of interchanges to ensure seamless multi-modal transfer”, to improve the ease of commuting across the city.
Shared mobility services, such as those offered by Ola and Uber, have rapidly become a part of the transport-mix. Agarwal expects that in the coming decade, car ownership will be virtually unnecessary due to extension of shared mobility models to mini-buses, which would facilitate intra-city transport at the touch of a button, be available to customers at short notice, adjust to small deviations in routes and provide comfortable seating. Such a service would have a lower road-area footprint per passenger, while making multiple trips in a day and providing a safer, more comfortable environment as compared to pooling services today.
However, he adds, “This would require suitable amendments to the Motor Vehicles Act (1988)”, which only allows contract carriages or stage carriages to ply as buses.
Bogota and Copenhagen have both been recognised globally for encouraging a broad shift to Non-motorised transport (NMT). In the Indian context, Bhopal in particular has taken significant strides in this direction with its Lal Sadak initiative.
Unfortunately, Mehta says that last mile connectivity has remained relatively absent from the discourse on planning in India. This has reduced the accessibility to public transport services. Gaps in these services have been filled instead by an array of actors such as e-rickshaws. The provision of feeder services is a large part of making public transport more viable for commuters. Agarwal recommends that use of the Metro services could also be tied-in with a free parking option.
Heavy congestion is not simply a problem on the larger roads. Most residential areas were designed keeping in mind single car parking. Gurpreet Singh Bindra, President of the Vasant Vihar Resident Welfare Association, says the neighbourhood struggles with congestion due to its proximity to major roadways and 16,000 students, who come to schools in the area daily.
Bindra pointed to school-traffic policies, which were suitable two or three decades ago, but are now in urgent need of updating as well.
An additional concern has been the frequent change in land-use, which makes effective traffic management all the more difficult. To address these issues at a neighbourhood level, the RWA committee has commissioned noted traffic expert, Rohit Baluja, to oversee the collection of relevant data and the “carving out of an internal traffic policy”. This is a work in progress and the RWA will be sharing the lessons of this exercise with the Delhi Traffic Police.
Mixed-use planning within a ‘compact city’ setting could be a solution, and has been the ‘traditional philosophy’ to reduce travel distances. However, such a shift would require a thorough understanding of traffic dynamics in and around the neighbourhoods.
There is no quick fix for congestion. This would require a multi-decade plan and a host of supportive policies towards effectively reducing this. What we do know for certain is that not doing so would prove rather costly.
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