Tag: intersections

Yet another startup idea

This time it’s an i-phone/android app. The motivation for this is the heavy advertising in the last few days for Mapmyindia GPS, on hoardings all over Bangalore. Again, I don’t know if this has been implemented before.

So this will be built on top of Mapmyindia or any other similar GPS. When you hunt for the shortest route between point A and point B, you can give two possible choices – shortest by distance and shortest by time. The former is the default choice that all GPSs currently use. This one is an app to provide the latter.

Now, each city will be mapped out as a network of intersections. And then, for each “edge” on this graph, we use data that we’ve gathered from other users of the app in order to predict the amount of time taken to travel. Of course, the prediction model is not going to be simple, and I’m willing to partner you (via my forthcoming quant consultancy firm) in developing it. It’s going to be a fairly complex model based on time-of-day, recency of data, outlier detection (what if someone stops off for lunch in the middle of an “edge”?) and all such.

So, now you have the city mapped out (for a particular instant) both in terms of distance and in terms of time, and in cases of any traffic jams or such, my system will help you find the quickest route to your destination. Should be useful, right?

Of course, the success of this app (like a lot of other apps, I guess) depends heavily on “network effect”. The more the users of this app, the better the model I’ll have in predicting time between intersections, and save you the headache of mentally trying to optimize the route to your destination each time you set out (like I do).

I’m pretty serious about this. If you think this hasn’t been done before, we can work together to get this up!

Road Widening is NOT the solution

The other day, walking down Dr. Rajkumar Road in Rajajinagar, I saw several signboards on the road, on shopfronts, on buildings, etc. protesting against plans for widening the road. Apparently they want to widen the road and thus want to demolish shops, parts of houses, etc. Looking outside my own apartment building the other day, I saw some numbers written on the compound wall. Digging deeper, I figured that they want to widen the road I live on and hence want to claim part of the apartment land.

Now, the logic behind road widening is not hard to understand – due to increase in traffic, we need more capacity on the roads and hence increasing their width results in increased capacity in terms of vehicles per unit time and so it is a good thing . However, before going headlong into road widening and land acquisition for the purpose, road architecture in the city needs to be studied carefully.

There are two primary reasons why trafffic bottlenecks happen. The more common reason at least in western nations is road capacity. Roads just don’t have the capacity to take more than a certain number of cars per hour and so when more cars want to go that way, it results in pile-ups. The other problem, which I think is more common in India is intersections.

It is going to be a tough problem to model but we should split up roads into segments – one segment for each intersection it is part of, and one segment for each segment between intersections (ok it sounds complicated but I hope you get it). And then, analyzing capacities for these different segments, my hypothesis is that on an average, “capacity” of each intersection is lower than the capacity of road segments between intersections.

Now how does one calculate capacity of intersections? Assume an intersection with traffc coming from all four directions. Suppose traffic approaching the intersection from north sees green light for fifteen seconds a minute. And in each fifteen second interval, 25 cars manage to make it past the intersection. So the capacity of this intersection in this direction becomes 25 cars per minute. I hope you get the drift.

I’m sure there will be some transportation engineers who will have done surveys for this but I don’t have data but I strongly believe that the bigger bottleneck in terms of urban transport infrastructure is intersections rather than road width. Hence widening a road will be of no use unless flyovers/underpasses are built across ALL intersections it goes through (and also through judicious use of road divider). However, looking at the density of our cities, it is likely to prove extremely expensive to get land for the widened roads, flyovers etc.

I don’t see private vehicle transportation as a viable solution for most Indian cities. Existing road space per square kilometer is way too small, and occupation way too dense for it to be profitable to keep widening roads. The faster we invest in rapid public transport systems, the better! I’m sure the costs borne in that direction will be significantly lower than to provide infrastructure to citizens to use their own vehicles.

Traffic signal policy

Is it fair on the part of the city government to direct people’s choices of routes by imposing a suboptimal timing plan on a traffic signal? Or is the government supposed to respond to demand and design the signals looking at the traffic in various directions? Which is supposed to lead which? Which is the hen and which is the egg?

Yesterday I passsed the airport road – victoria road T-junction on the way to office and noticed that the average perceived waiting time on the Victoria road side was significantly higher compared to that of the two branches of the Airport Road meeting there, which was clearly inefficient. Though it is very likely that it has come about because of a generally poor design of the signal, it could also be by design – because the government wants to disincentivize people from using that route.

Given that we are not yet at the libertarian ideal of  “private roads for everyone”, in most municipal regions, the government has the responsibility to build and maintain roads. And given constraints such as the Braess’s Paradox, occasionally it might actually make sense for the government to occasionally direct traffic, rather than leaving it for a free-for-all. I suppose efforts such as converting roads into one-ways are in the same direction.

So given that the government has the monopoly to “give” roads, does it have the right to “take” away roads? If it does, it means that it is effectively trying to control how and where people move. Isn’t that against stuff like freedom of movement? It’s kinda scary.

But if the government doens’t have the right to “take away” roads, what happens to stuff like one way roads, etc.? After all, when you make a road one way, you are imposing a higher cost on certain people (who are willing to brave the heavier traffic in order to move in the “opposite” direction so that the total cost to society at large goes down. Sinilarly, when you put a road divider, you cut off access to certain intersections which would have been very convenient for some people in the larger interest.

So does an elegant solution exist to this problem, assuming that we cannot put tolls on all roads? In principle, putting tolls on roads is fair because we are already taking toll from motorists in non-monetary ways – such as by not maintaining the road, or by subjecting them to too many intersections, or by allowing so many vehicles on the road that reduces the speed of the road. Given all these costs that are imposed on motorists, monetizing them is not tough in principle.

However, politically it is a huge issue and is unlikely to happen for several years to come. In this context, does there exist an elegant solution to traffic management and regulations, that can compensate for inconvenience caused to people in the name of interest of the society-at-large?