Wednesday , 2 December 2020

Flyovers in Mumbai End-User Evaluation of Infrastructure Projects

Mumbai’s major traffic challenge has been its linear geography. The location of its business centre at its southernmost tip has only added to its woes. While the two arterial roads – Eastern Express Highway and Western Express Highway – serve as feeder from the suburbs to the island city, the Central, Harbour and Western Rail corridors aid in pushing the commuter load from intermediate rail stations to roads through secondary transport modes like taxis, buses and autos. Suburban rail stations of Kurla, Bandra, Thane and Kanjurmarg serve as pivot points for channelising the commuter flow (Illustration 1). As per MSRDC (Mumbai State Road Development Corporation), the links to Navi Mumbai through Airoli and Mankhurd are already reaching their peak carrying capacity. There have been other initiatives like the Jogeshwari-Vikhroli, Santacruz-Chembur links and even Mumbai Metro to give a method to the madness of traffic in the city. The construction of flyovers, however, needs to be seriously analysed.

Commuter Traffic along Eastern Suburbs

Eastern Express Highway caters to the requirement of commuter flow to the business district from central suburbs up to Thane and from Navi Mumbai (Suman Nagar onwards). MSRDC has built a series of flyovers in the recent past to ease the traffic on this route. With the commissioning of the Lalbaug flyover, all the planned flyovers except the one at Suman Nagar – which is in its final stages – have been actually completed.

The average commute time – despite the commissioning of almost all the flyovers – from Thane towards CST – is 93 minutes in the morning and 130 minutes in the evening. This, when people using the public transport, which makes for the majority of the volume, do not actually use the flyovers. At the same time, the commissioning of these grade separations has not eased the traffic on the below road sections.

Travel Time Analysis: Thane – Nariman Point

Thane is one of the key destinations for residential projects. Considering the concentration of the housing activity around the Thane-Borivali link which is shaping up rapidly, the transport authorities like BEST and MSRTC have introduced several special services from key areas to South Mumbai. Also, majority of the residents belong to the corporate segment and thus travel in their own vehicles. Hence, the traffic inflow on the Eastern Express Highway has increased manifold. During the pre flyover era, the average commute time between Thane and Nariman point by road was approx 80 minutes and, despite the flyovers, it has, in fact, increased by 15%.

Table 1 provides the snapshot of the travel time along the key segments of the Thane-Nariman Point route before commissioning of the flyovers at Mulund, Sion, Matunga, Parel and Lalbag. Originally planned as one-way flyover at Sion, Dadar TT and JJ flyovers are the only ones which were operational when this data was captured. The segments where vehicles crawl are highlighted.

As seen in the table, there are segments where it takes exceptionally long for vehicles to cross the stretch. The situation worsens in the evening. With grade separation, it is expected to reduce this time significantly for those who take the flyovers and to some extent, for the vehicles which do not take the flyover route. The latter are taken by majority of commuters, especially those who use public transport.

Table 2 gives the segment-wise travel time after the commissioning of the flyovers. The details clearly point towards one question – is the public investment in such projects meant for the class of commuters who own vehicles or who travel by taxies? Another aspect to look at is that the vehicles which take all the flyovers now cover the travel stretch in approx 80 minutes which is the same as it was in the pre flyover era.

Table 2 shows an increase in travel time on JJ flyover indicating more commuters with own vehicles have changed their routes, while the commuters on Parel-Byculla route who use public transport (thus, avoiding the Lalbaug flyover) have got some relief. The details throw light on the challenges faced due to variation in lanes. Variations in lanes leads to bottlenecks as the frequent changing of lanes by the drivers leads to traffic jams and even accidents. Further, the starting and ending point of a flyover are critical as these are points where one lane either gets added with grade separation or converges leading to directional changes in vehicle movement which further leads to bottlenecks at these points. During peak hours, this has an upstream effect leading to vehicle pile-up. Table 3 gives the details of lane variation along with signal-benefit to the vehicles using the flyovers.

Capacity augmentation for Mumbai roads is now next to impossible. Taking vehicles off the road is the solution. But then, that may not be possible. So, devising creative ways to make people follow is the way forward.

It becomes clear that despite the commissioning of infrastructure projects, the common man travelling by public transport is the least benefitted. Also, the users of these assets too do not benefit entirely from them. The travel time on the flyovers in the evening indicates this strongly as the travel time in the return journey is shown to have increased by 30%.

Causal Analysis for Speed delays

The increase in the travel time attributes to speed delays. There have been varying causes for this like the common ones – vehicle breakdown / accident, water logging in monsoon, irregular footpath width, on-street parking, etc. Plus, some impact the lane width and thereby, the carrying capacity of the transport channel. It is synonymous to an artery blockage leading to the jamming of blood flow to the heart that further leads to a heart attack. In this case, the blockage is daily and the flow to the heart of city i.e. the business district is impacted. To worsen things, the heart of Mumbai lies in the extreme end – at its southernmost tip.

The much talked about issue of potholes is also a reason for speed delays. The roads in our country are always planned on a higher level than the surroundings, often resorted to by land filling to match the levels. Over a period of time, with development around these roads the subsoil water from surrounding areas percolates beneath the crust weakening the filling and leading to the sinking of road surface. That then leads to potholes. The main attribute to the potholes on concrete surfaces like the flyovers is poor compaction which is purely a workmanship issue. The causes for speed delays are purely attributed to the planning of road geometrics and alignments.

Potential Remedial Measures

It is clear that capacity augmentation for Mumbai roads is now next to impossible. Taking vehicles off the road is the solution. But then, that may not be possible. So, devising creative ways to make people follow is the way forward. Listed below are some such suggestions:

A. Complementing BEST / NMMT Initiatives to run the Mumbai version of BRTS.

The BEST has taken a commendable step in introducing AC buses on various arterial roads as well as roads connecting the suburbs. The challenge here is that these buses get occupied to their full capacity at the starting point itself, thus forcing the other potential travellers to resort to personal transport. Staggering the starting points at key commuter catchment areas and creating parking facilities near these starting points shall induce a habit of ‘Park & Ride’ for commuters.

B. Introducing long distance shared taxi service from key locations on arterial roads like the one described in this article.

C. Revising parking pricing policy to occupant based parking charges at designated parking lots in the city. For example, if the parking charge for a self driven car is `100/-, this shall be reduced to `25 if the car has four passengers.

D. The concept of point C can be extended to taxies as well. The meter of taxis shall be calibrated in such a way that if the taxi is occupied by four persons, the charges would be `100/- but the same can be scaled to double the charge if someone travels alone. The taxi unions are likely to welcome such a move. Points C & D can be alternatives for congestion tax which was thought of for the city of Mumbai earlier.

E. Leveraging e-Governance initiatives to allow staff to work from their preferred locations – different offices to save on their commute time, increase productivity and also reduce vehicular traffic on roads.

F. Creating projects of catalytic nature to induce urban sprawl, thereby diverting the traffic movement.

G. Overcoming border issues like Mulund–Thane, Mulund–Airoli, etc. for autos plying in suburbs thereby reducing the aggregation of autos at these points which obstructs traffic flow.

H. Installation of displays at key junctions giving vehicle volume information on road segments ahead so that drivers can shift to alternative routes. Such loop routes also need to be created. It is seen that the drivers do follow such loops on their own. One such effective loop exists between Kurla and Priyadarshni which helps avoid congestion at the Suman Nagar Junction.

I. Making facility for

• Other states’ vehicles to record their entry in city and pay fixed fees.

• Online Buying of toll tickets / Passes

• Two way toll tickets to reduce queuing time at toll booths.

• Multi mode fare card for easy shift from one mode of public transport to the other.

Considering the fact that London’s bus network, which is one of the biggest in the world, has 8,000 buses, 700 bus routes, and carries over six million passenger daily, the BEST service in Mumbai – though nearly half its size with a fleet of 4000+ buses and 350 routes – has higher efficiency as it carries 4.5 million passengers daily. The need of the hour is to make ways to scale up this public transport mode by reducing the other vehicles on city roads.

Praful Gharpure
Architect – Urban Planner
Government Industry Solution Unit
Tata Consultancy
Services – Mumbai

Mumbai Transport:
Some facts
Population: Over 18 million. Daily trips: About 14 million trips a day, with about 88 per cent of the trips catered to by the suburban railway and the public transport bus services provided by Brihanmumbai Electricity Supply & Transport (BEST). BEST carries 4.5 million passengers every day which is 75% of train commuter load. The population growth in the city has resulted in the increase in vehicular population from 0.15 million in 1971 to 3.5 million in 2008

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