Time to stop the buses?

Published: 27 May 2011

• I AM a bus driver on the 24 route and I note the warnings about riding Boris bikes in London’s pollution.  

Some of your readers may have noticed me stopping the bus engine at traffic lights or in traffic queues.  

The times achieved are quite surprising. 

On two days of early shifts this week I recorded engine stopped times of 51 and 53 minutes. 

These were not long shifts and the engine was not stopped for the full amount of time possible, only what I could achieve relatively easily with the existing bus set up.  

The intention behind the exercise is to find evidence to support the idea of incorporating stop/start technology into stage carriage buses used on congested bus routes.

Last year I contacted Radio 4’s More or Less programme with a question about the amount of time spent idling at red traffic signals, primarily on route 24 that I drive.  

They asked me to record some times for the programme which went out in December last year. 

It was introduced by Tim Harford from Stockwell garage, home to No 24 buses.   

Their research for the programme produced some interesting results which can still be heard, about eight minutes into the programme, by going to the More or Less programme archive at:http://www.bbc.co.uk/programmes/b00wdkf9

It was only after recording those quite lengthy red traffic light times (10 to 15 minutes per trip during the day) that it occurred to me that both fuel and atmospheric pollution in our congested streets might be saved if the engine could be switched off.  

I knew that some cars already use stop/start technology, allowing the engine to be restarted by depressing the accelerator when able to move forward again.

As bus engines are presently set up, it is not easy to stop and quickly restart. The starter inhibitor prevents the engine being started with the automatic transmission engaged and, when the engine is stopped, it takes two to three seconds for the engine management computer to reboot before it will allow the starter motor to operate.

The idea of stop/start technology for buses has now been passed to London General Bus Company management for their consideration and I have written to Boris Johnson, in his capacity as chairman of Transport for London, to ask for his support and, potentially, the support of TfL in persuading bus engine manufacturers such as Cummins to take up the idea.  

It remains to be seen if anything will come of the idea.

Noel Staples, SW11