A spectacular bridge that few use

That’s the Bandra-Worli Sea Link he meant, apparently now the bar for other, newer bridges and highways. And that’s the Mumbai Trans-Harbour Link he also meant, the 22km bridge from Sewri across the harbour to Uran. It’s been open to traffic for just over a month now, and while I haven’t used it, I know at least one person who has, and who wishes he can take it again. And again. “So smooth," he sighed.

Ten days after it opened, news items told us some early MTHL numbers. Starting with 28,176 on the first day and 54,977 on the second, a total of about 309,000 vehicles had already used the bridge in those 10 days, we heard. On average then, over 30,000 vehicles drove across it daily. The revenue from tolls was about ₹61.5 million, or about ₹200 per vehicle. This made sense, because the toll for traversing the whole bridge is ₹250, with smaller amounts for shorter stretches.

Sounds like a lot of cars? Sounds like there was plenty of early curiosity about this sparkling new addition to the Mumbai landscape—or seascape, rather—and that settled down to a more routine flow of vehicles? Maybe so. That’s the way things usually are with sparkling new additions. When the Bandra-Worli Sea Link opened in 2009, plenty of Mumbaikars drove across for a joyride, resulting in a huge rush in those first few days. The rush subsided as the novelty wore off.

By its designers’ own admission, the Sea Link was designed to transport over 100,000 cars daily. The actual number is about 32,000 daily. Less than a third of capacity.

Will something similar happen with the MTHL?

To answer that, of course, we need to wait for a while and then measure the traffic on the MTHL. By now, it has been open just over a month. Time enough to draw some conclusions. And indeed, news items popped up, 30 days on, to tell us some month-old MTHL numbers. The bridge “turned one-month-old on February 13", says one report, “and a total of [813,000] vehicles used the bridge in the past month".

Ten days, and now 30 days: you’d expect the second count of vehicles to be three times the first, or close at any rate. But three times 309,000 is 927,000. The actual count is 813,000—which gives us a daily average, for the month, of 27,100 vehicles. That’s a 12% drop-off from the 10-day count, and a better than 50% drop-off from the novelty-fuelled rush of the second day.

None of this should be surprising, really. Novelty wearing off is one reason usage drops off. Another reason is the cost of the toll. ₹250 may seem reasonable for a bridge across the sea that’s 22km long. But for a lot of motorists, it is nevertheless a reasonably large chunk of money, a definite deterrent to using the MTHL.

Besides, as with the Sea Link, there’s another number to consider: capacity. Actual usage is one thing, but how many vehicles was it designed to carry? Put another way, what daily count was predicted for the MTHL when it was being built, and then opened?

The answer, some reports suggest, is about 70,000. Take a moment to let that sink in. Usage over the bridge’s first month averaged less than 40% of its capacity—or as another report headlined it, “62% short of projection". Even on that heady second day when curious Mumbaikars took their MTHL joyrides, the traffic on the bridge was less than 80% of its capacity.

What accounts for this? Why does usage fall so far short of capacity?

Well, you can find an explanation in those reports about a month of MTHL usage. A Mumbai Metropolitan Region Development Authority (MMRDA) commissioner is quoted thus: “The number of commercial vehicles is not significant and therefore the projected vehicle count has not been achieved." Indeed: of the 813,000 vehicles that first month, 797,000 were cars. According to the Commissioner, “outside vehicles [don’t know] about this bridge yet". As time goes on, he said, “the count of commercial vehicles will grow as the users will become familiar with this new connectivity".

With this growth and other measures, the commissioner asserted that in 2024, “close to 40,000 vehicles (per day) are expected to use the link." Still only 57% of capacity, but consider a more subtle implication. We’re at 27,100 vehicles per day today. What will it take for that average to rise to 40,000 after 11 more months? Some simple arithmetic tells us the answer: The daily count will have to average nearly 42,000 vehicles for the rest of the year.

Whether the bridge will attract that kind of traffic remains to be seen. But even that number is still, you will note, under 60% of capacity. That is, even the people who built the bridge don’t expect it will attract the number of vehicles they designed it for. Not even close.

What does that say about the bridge, about design, about planning?

What does it say about priorities?

One study showed that on average, each car moving along the Sea Link carries 1.75 people. For the MTHL, let’s arbitrarily raise that to three. Then the MMRDA Commissioner’s figure of 40,000 vehicles per day means 120,000 people are using the MTHL every day. That seems like a lot of people.

Until you compare it with the number of commuters in the city of Mumbai. In a previous, similar, column about the Sea Link (https://t.ly/b0Thx), I did a back-of-the-envelope calculation about this. It showed that about 150,000 people arrive in South Mumbai by commuter train every hour during the morning rush hour. (And similar numbers leave during the evening rush hour.)

That’s right, the trains ferry more people into the heart of the city in an hour than those who use the MTHL all day. And there’s bus ridership, not yet accounted for.

The point of all these numbers? It’s a spectacular bridge and a stellar feat of engineering, the MTHL. But let’s never forget whom it was built for: the small fraction of the city’s residents who drive cars. Let’s also never forget who seem to be using it: a small fraction of even that small fraction of the city’s residents.

Once a computer scientist, Dilip D’Souza now lives in Mumbai and writes for his dinners. His Twitter handle is @DeathEndsFun.