idling at Traffic signals ~ should one switch off the engine ?????

Traffic choking is common is every other city ~in roads like OMR, often vehicles get struck – and in some signals, one has to wait for long – there is no guarantee that vehicle could pass in one green as it could close when even half of the queued vehicles could not pass through !

This is a photo that appeared in Aug 2009 in - www.treehugger.com – instructing that idling of vehicle is not allowed. If one stops at Red signal, engine should be stopped and not allowed to idle.  Don’t restrict yourself to what you do or what you see around. In cold and hot climates people may let their cars idle to achieve a comfortable temperature while they wait in their home. Some people also believe that it is better for their car to let the engine warm up, a myth perhaps.

Another article in Daily Mail in Sept 2008 reported that -   Motorists could face £20 spot fines if they leave their engines running while stuck in traffic. It stated that Traffic wardens will be able to issue the penalties  -  after a warning  -  in a bid to cut down on pollution. That was about a pilot scheme in Shoreham-by-Sea, West Sussex, targeting  areas where exhaust emissions build up unnecessarily, such as rail crossings and town centres.But drivers branded the plans as yet another round of the war on the motorist. The AA pointed out that to switch off an engine and start up again within a minute actually uses more fuel than letting it idle.

The Department for Transport said it had issued guidance to councils stressing that they should not issue a £20 penalty notice without first giving drivers a warning.Rule 123 of the Highway Code says: 'If the vehicle is stationary and likely to remain so for more than a couple of minutes, you should switch off the engine to reduce emissions and oil pollution.

~ this article in ‘thisismoney.co.uk’ seeks to bust the myths on turning off the engine in traffic. Here is the article partially reproduced :

I've noticed more and more drivers will cut off their engine in traffic, which I suppose is down to modern cars being fitted with 'stop-start' technology.I don't have this on my car but wonder if I should be turning off the engine more often when I stop.I'll do it in a long traffic jams when you don't move for several minutes but have always thought doing it more often will damage the engine and / or actually use up more fuel.

Stop start: When does it make sense to turn your engine off?AA spokesman Luke Bosdet replied: The rule of thumb is that if you're going to let the engine idle for more than a minute or two then it is probably worth turning it off.Doing so more often than that can be arduous for both driver and the engine, and it's important to remember that each time you fire the engine you're making a demand on the battery.

It makes sense that leaving the engine running will use a bit more fuel and that's why modern cars, even quite simple ones, will often now include start-stop technology that turns the engine off when the car stops.However, anyone with start-stop knows that the system will turn the engine on again to recharge the battery. So it's not as simple as just turning the engine off when you stop.

There's also the environmental impact to consider. We've argued that drivers of cars with stop-start technology should be exempt from congestion charge in cities.Richard Seymour, spokesman for Toyota and Lexus, said: The start-stop systems in our cars monitor a number of things within the car to determine whether it's safe to switch the engine off.Some drivers tell us they think something is wrong because the engine hasn't stopped when the car has stopped, but the system will measure things like temperature of the engine and the voltage of the battery to check that it is safe to switch off.If the engine is too cold or the battery too low, or if safety checks like the doors being closed aren't in place, then the system won't work.

We wouldn't recommend drivers turn off their engine at every stop in traffic if they don't have a start-stop system. Modern cars may have brake systems that rely on the engine to create a vacuum that makes the brakes work more efficiently.If the you know you'll be stationary for a while it's worth it, but stopping the engine for very short periods gives negligible benefits.

So – what would you do in a traffic signal next time !

With regards – S. Sampathkumar

3^rd Sept. 2015.