The Green Highway

# How green is mass transit? Add to ...

I was taking the bus to the subway station the other day and realized the bus was taking a greater beating than I generally put a car through in a test drive.

The bus was full and I was standing. I held on for dear life to keep from falling backward as the driver tromped the pedal and the bus accelerated hard. I held on tighter as he braked sharply at each stop. We all swayed like a big blob as the bus rounded fast corners. The crashing and banging as the bus hit bumps was deafening. Another hard stop and we all lurched out. It was a horrible ride but I was doing my bit for the environment. Or was I?

Well, that particular bus was jam-packed (about 50 passengers) so the fuel used per passenger kilometre was pretty good. But diesel buses in the city only get about 3 mpg (78.4 litres/100 km). Still with 50 passengers we were getting about 1.5 litres/100 km per person and that’s even better than my little diesel car. However, buses often travel with six or seven passengers or fewer (zero when they’re going back and forth from the garage). Lots of cars get 8 litres/100 km, so if the bus has five or fewer passengers, the fuel-efficient car delivers better fuel economy per head. If the car has two people in it, it is doing better than a bus with 10.

Now someone will quibble about the math and the fuel economy of my examples, but you get the picture.

At least half the buses in the Toronto fleet are hybrid, so that means when the driver floors it, there’s also a little burst from the electric motor. And when he hammers the brakes there’s some regenerative brake energy charging the battery. So my numbers can be played with. But when the vast majority of personal transportation is with private cars and trucks, you can see how important are improvements in automobile fuel economy. What are the car-versus-bus numbers going to look like if we actually get a fleet average of 50 mpg (U.S. gallon) or 4.7 litres/100 km in 2025?

In spite of all the attention paid to public transit, the car is king because it takes people where and when they want to go by the most direct route. I don’t think we’ll ever see public transportation luring a significant number of people out of their cars, although the rising price of gas is increasing transit ridership slightly at the moment.

I did see something last week, however, that could tip the car-versus-bus balance a bit. A fleet management company paid for a study, which suggested that eco-driving techniques could reduce the fuel consumption in public transit buses by up to 18.7 per cent.

SmartDrive Systems wired up a bunch of buses with spyware to measure acceleration, braking, turning, idling time, fuel consumption and so on. The company collected the data but it was also always on display to the drivers at the wheel providing in-vehicle instant feedback on improving fuel economy. Drivers who paid attention to it discovered they could increase fuel economy by up to 18.7 per cent. That’s a huge improvement. Car companies spend billions to get an extra per cent or two.

About 25 per cent of the bus drivers in the program succeeded by paying attention to smooth acceleration and deceleration. They also reduced excess idling and avoided hard turns. All that clearly was a benefit to the passengers, too.

Increasing the fuel efficiency of the average car is the way we save significant amounts of energy. But it would be good to see bus fleets take simple measures to do what they can to get with the program.

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