Trivandrum Metro has been hogging the spotlight in all forms of media in this part of the world, for a while now. Every keyboard warrior has been prolific with their comments, criticisms and creative solutions – even coming up with innovative ideas that would make any rail expert to sit and ponder for a minute.

All through this clutter of swashbuckling, one emotion that runs through appears to be one that of disappointment. Disappointed that Trivandrum has been relegated to the number two spot after Kochi. Disappointed that Trivandrum stands to get a light metro, whilst other metropolitan cities in the country get to enjoy medium metro. Disappointed that there is only one line proposed for the foreseeable future. So on and so forth.

Slogans demeaning E Sreedharan, also known pan-India as the Metro Man, are rampant. Some even suggesting that he has a vested interest in the downfall of Trivandrum. Politically triggered champs waste no time in pointing fingers at everyone else other than their own.


Never have I seen such collective empathy towards one project as this. It is encouraging and at the same time, quite disturbing too. Disturbing to me specifically because much of the verbose comments that are being bandied about show a lack of understanding of how a Metro Rail System is planned and works. That ignorance takes shape in the form of personal slander of a gentleman who is respected not just here, but the world over in the world of Railways.

What is a Metro?

It is a high capacity transit system for urban areas that are run on exclusive segregated tracks. They can be elevated, at ground or underground. Although, there are no universally accepted definitions, they can largely be classified as light, medium or heavy metro systems. Technically these classifications are brought about by their axle load, power consumption, operational speed etc, but most importantly its passenger carrying capacity.

Capacity of a Metro

This is a function of very many factors. The number of cars in a train, the intervals at which it operates, its operating speed and the capacity of the cars itself. The distances between stations and the size of platforms etc have a say too.

How is a Metro system chosen?

The feasibility of a metro is based on a number of factors: size of the city, topography of the land, land availability, number and radii of turns needed, available power etc, but most importantly, the capacity needed to meet the traffic demand of the city. Traffic demand is estimated not on just the overall population of the town – which seems to be the understanding most people have – but it is a function of the passenger movement demands from one point in the city to another point. When all these are put together, the demand of moving a sertain large number of passengers through a corridor emerges. The density of micro-areas of the city, the residential area spread, the business centres etc all play a role in this.

In that sense, the call for a touch point with Technopark does make sense to me, but also almost certainly does not call for a line that goes parallel to the original proposed alignment. Perhaps a spur might do the trick.

Traffic demand is expressed as passengers per hour per direction (pphpd). A metro system is planned for the peak hour pphpd demand. The peak hour pphpd in Trivandrum city is estimated to be only 12000 pphpd. This number squarely lies within the ‘light’ metro range. Future demand is estimated at a maximum of 16000 pphpd in 2041. A medium metro makes sense only if this number crosses 18000 or 20000 pphpd.

Light Metro System

A light metro system has its advantages in a city like Trivandrum, where steep gradients (Kesavadasapuram, Pangappara, Pattom etc) and tight junctions (Ulloor, Sreekariyam etc) can be navigated easily. Elevated viaducts through the road medians, arguably the cheapest method to insert a metro system suits well for the city and a lighter infrastructure for a light metro system would augment  that. Stations will be with side platforms and naturally ventilated, thus reducing the footprint of the stations (thus land cost).

The capacity of a system is not just the carrying capacity of the train (number of cars, size of cars), but also the intervals at which it runs (determined by the operational speed and the proximity of stations). So as the demand increases the operations can introduce more rolling stock (trains) into the line and reduce the intervals, the shortest interval being 90 seconds. Metro railway uses modern Communication Based Train Control (CBTC) systems that allow accurate error free safe signaling system that can control these intervals and headway (distance between two trains).


Metro systems are capex heavy. Trivandrum metro is estimated to be north of Rs 3500 crore or $0.5 Billion – which as metros go, is an economical number. Nevertheless, it is a different matter to keep the metro running sustainably. World over, metros seldom become entirely profitable on its own. Singapore government subsidises the capex, leaving the metro operator (SMRT) to manage the opex and keep it profitable. HongKong Metro (MTR), one of the best metro systems in the world, is really a huge real estate developer that subsidises its metro.

Farebox collection (revenue from ticket collection), especially in the beginnings can almost never match the opex. Metros consider additional revenue generating mechanisms (Transit Oriented Developments – Japan, HongKong), (Station Naming Rights – Dubai) to lighten the load on exchequer.

Therefore it is imperative that the choice of a metro system is prudently done, which is what is normally done and is being done in Trivandrum too. Engineers who plan a metro system hardly goes with the ambits of politics or populism. They go by hard numbers. So the vanity calls of wanting to have a medium metro just because another city has one, or even extending it to Kollam or Ponmudi etc have to be done with.

Because what matters is not just constructing a metro system for the sake of having one, but it is about constructing the most appropriate system that meets the present and future demands of the city and more importantly one that can be sustained in its operation.

By Manoj

Leave a Reply

Your email address will not be published. Required fields are marked *

Verified by MonsterInsights