Namma Metro Phase I route map (Source: Wikipedia)

Namma Metro service covers 3% of city’s commuters

8 min readJul 16, 2017

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Phase I of Bengaluru Metro is finally running. There has been some discussion of whether it has reduced the traffic congestion in the areas where Metro services are in use.

Here I take a look at the kind of coverage Metro Phase I provides to Bengaluru’s commuters. Using some simple calculations, I estimate that Metro Phase I serves less than 3% of all commute needs of the people of Bengaluru. For the remaining 97% of commuters, we have to continue to rely on good old BMTC buses, two-wheelers, private cars, cabs, autos, etc. Hence Phase I is unlikely to reduce congestion significantly.

Let’s start with some basic statistics about Phase I. It consists of two lines, the North-South Green Line (24 kms, 24 stations) and East-West Purple line (18 km, 17 stations). The ridership currently stands at around 300,000 commuters per day.

Geographical Coverage

First, let’s look at geographical coverage. Consider a core area with an arbitrary radius of 7 kms which contains 35 of the 41 stations in Metro’s first phase.

Being generous, I assumed that even the lazy Bangalorean would walk up to half a kilometre (say a 10 minute walk 0n Bengaluru roads) to catch a Metro ride. So each Metro station covers a small circle of half a kilometre radius, as in the picture below.

The idea is that if one has to take an auto ride or get to the station in some other mode, it adds to the cost of the ride, in term of money, time, effort etc. So I limit the coverage to areas within a 10-minute walk. There will be exceptions, of course, but let’s start with this assumption for now!

The core area contains 35 Metro stations. This gives us an impressive 17.9% geographical coverage of the core area, which is not too bad. Looking at a peripheral area of radius 14 kms, the coverage drops to just 5.4%, as there are only an additional 6 stations in the periphery.

For the sake of simplicity, I am ignoring the exact location of each Metro station and any possible overlaps between stations.

Next, let us compare this with the geographical coverage provided by Bengaluru’s city buses.

Comparison with city bus transport (BMTC)

Recently BMTC released data about its bus routes and stops, to encourage development of applications. I discovered that the data did include the geolocations of the bus stops, and I used it to plot the bus stops on the same map as the Metro stations (shown as blue dots in the image below).

In the core area (7km radius), there are 500 bus stops. Given that bus stops are much closer, I assumed a shorter walk of 300 meters (6 minutes), and ignoring overlaps as before, this gives us a coverage of 91.8%.

Looking at the peripheral area (14km), there are 1200 bus stops. Assumed a slightly longer walk of 350 meters, we get a coverage of 75%.

Red stars are Metro stations, and the blue dots are BMTC bus stops.

In the picture above, there are large spaces without blue dots, and most of these correspond to inaccessible spaces such as lake beds, military installations, etc.

Commuting coverage

While the numbers show that the Metro covers about 18% of the core area, it really doesn’t mean that it serves 18% of commuters in this area. To find that, one has to consider all the possible places that the commuter may want to go. A commuter is going to consider using the Metro service only if both the source and the destination of the commute are served by the Metro.

As a first cut, let us assume that it is equally likely that a commuter may go from any point to any other point in the city. Since Metro serves only 5.4% of total area (about 1 in 20), when we look at commute source and destinations, only 1 in 20 source points and 1 in 20 destination points. In other word, Metro would cover only 1 in 400, or 0.25% of all commutes! In contrast, BMTC, with its 75% area coverage, serves 56% of all commutes.

Since the Metro is concentrated mostly in the core area, let’s look at commuters there. A commuter in the core area may need to go to another point in the core area, or to a point in the peripheral area.

For people in the core area, the Metro serves 17.9% of the starting locations, but only 5.4% of the destinations. Combining them, we see that Metro serves about 1% of commuters in the core area. BMTC serves about 69% of core area commuters.

Next, given that people tend to live in the suburbs and travel to the city centre, let us assume that commutes are more likely to begin or end in the core area. Let’s say that a commute is twice more likely to end in the core area (7 km radius) compared to the peripheral area (14 km radius), which is 3 times as large in area. This gives us 0.75% for peripheral area commuters and 2.5% for core area commuters. (BMTC: 64% and 79%).

Finally, as a best case, let’s assume that all commuters in the core area want to travel only within the core area. Even with this restriction, the Metro covers only 3.2% of all commutes within the core area! (BMTC: 84%)

Metro, BMTC and other modes of transport

Vehicles registered in Bengaluru in 2016 (Source: ET)

Bengaluru’s population of 85 lakh has over 66 lakh vehicles registered, of which 46 lakh are two-wheelers and 13 lakh are cars. In contrast, BMTC, its public transport system, runs just over 6200 buses. Using these numbers, I have tried to put together a rough guess of the share of all the commuters for each mode of transport.

BMTC has the largest share, 45% of all commutes, which seems fairly reasonable given the 56% commute coverage that it has in the peripheral areas of the city.

BMTC provides services to all parts of the city and beyond. It has 2200 stops in all, some of which are more than 40 km from the city. In the peripheral area that we considered (14 kms radius), it provides 1200 stops, covering over 75% of the area. In the core area, it has 500 stops, for a coverage of 92%. BMTC’s daily ridership is 50 lakh. Sadly, instead of growing, BMTC has been steadily losing buses from its fleet over the last 3–4 years.

Compared to the BMTC, Metro Phase I has a 3% share, which exceeds its small coverage of between 1% and 3%.

So even this ridership is higher than estimated. What explains this?

Given Bengaluru’s pathetic traffic, one can save large amounts of time and energy by taking the Metro. So commuters who need to travel long distances are going to make more effort to use the Metro services. Also the Metro is certainly attracting some commuters who would otherwise be using means other than a bus to commute.

Caveats

There are many other issues such as Metro’s capacity, changing pattern of commuters due to availability of Metro, the density of people living in different sections of the city, etc. which I have not considered here. This piece is focused strictly on the geographical coverage of Metro, as compared to BMTC.

Some might argue that public parking at the Metro stations enables more people to access Metro (beyond the 10-15 minute walking distance). This is true, but thanks to the lack of space and planning, most Metro stations in the core area have little or no parking space in Bengaluru. Only some peripheral stations (like Mysuru Road station) have significant parking. But even these are small in comparison to the ridership (parking for 2,000 two-wheelers as against 3 lakh ridership), and are not going to seriously increase the coverage.

I have come across some reports which suggest that a majority of commuters commute short distances (less than 5 kms), but I could not find any solid data on commute patterns such as this. Access to good data on commute patterns would help to make this model much better.

Phase II and beyond

Namma Metro Phase II (Source: Wikipedia)

Note: With the addition of the red, blue and yellow line, the centre of the Metro system will decisively shift to towards the south-east, reflecting the faster development of the city in that direction.

The Phase II proposes to add 90 kms of additional track and 74 new stations in all, including extension of the two existing lines and addition of three new lines.

When Phase II of Namma Metro gets ready in 2023, it will have 60 stations within the core area, increasing the geographical coverage to 28%, enabling more commuters to ride the Metro. It will have 55 stations in the peripheral area, increasing the coverage significantly from 5% to 15%. While this sounds promising, it is scheduled to complete only in 2023. Given the relentless growth of the city over the last many years, it seems that the Metro is barely going to keep pace with the needs of the commuters.

Conclusions

The Metro system by itself provides too little geographic coverage and serves the few lucky people who live near a Metro station and commute to a place not too far from another Metro station. Metro Phase I serves only 3% of the city’s commuters, and Phase II may improve that, but it depends on other factors such as the rate of population growth.

Access to Metro can be improved by integrating the different transport systems. For example, every Metro station should be within 2–5 minutes walk of a bus stop and auto stand. In stead of large parking lots, Metro stations should provide space for bus-stops. Metro feeder buses from/to residential neighbourhoods during peak commute times would help increase access to Metro.

Without such measures to improve access, a majority of commuters have no choice but to depend on personal vehicles, BMTC buses, auto and cabs. That is not a recipe to reduce the traffic congestion on our roads.

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I am interested in public data analysis, machine learning and Origami.