Idling at Redlights

1. Jun 5, 2014

anubodh

I want to know that how much idling occurs at redlights (in percent) out of the total idling done at various times and places?

2. Jun 5, 2014

Staff: Mentor

Depends on where you live/drive.

3. Jun 5, 2014

Greg Bernhardt

I guess write a personal log and find out?

4. Jun 5, 2014

anubodh

Can you tell on an average like more than or less than x%?

5. Jun 5, 2014

Staff: Mentor

It is route-dependent, e.g., the length and number of lights, in conjunction with traffic density and scheduling of the lights.

I've driven the same route at different times of the day. In the early morning, I found that the lights were synchronized such that it was not necessary to stop or if I had to stop, it was short. Traveling about 1 hour later, I would have to stop frequently, and usually the traffic density was greater. The lights were not synchronized for smooth traffic flow.

One could quantify the problem by measuring the rate of traffic flow as a function of time, and how many cars must stop at a particular intersection. That would have to be done at each intersection on each route, or at selected intersections. The problem is complicated since cars may enter or leave the traffic flow at intermediate intersections where lights may or may not be present.

6. Jun 5, 2014

BobG

The actual question was to compare idling at red lights to idling for other situations (not what percent of the morning commute was spent idling).

That would be very hard to estimate. You'd have to actually observe the idling behavior of a lot of people and your results would vary substantially depending on the location/season/etc that you made your observations (people in Alaska are much, much more likely to leave their vehicle idling out in the parking lot while shopping/dining out/etc in the middle of the winter than people living in a warmer climate would, for example).

7. Jun 5, 2014

lendav_rott

I'm usually idling behind someone who is driving with 2nd gear in a 50kph zone :<

8. Jun 5, 2014

Staff: Mentor

Where I live I have to drive through lights wherever I go. Where my Dad bought a country house I have to drive 30 kilometers to the first crossroads with lights. It is obvious that the answer to the original question is different in both places.

9. Jun 5, 2014

edward

A bit off topic but there are already several vehicles on the market that stop the engine when the vehicle is not moving. Idling when the vehicle is stopped is a great waste of energy.

http://www.transportation.anl.gov/pdfs/EE/642.PDF

The thing that really bugs me about red lights is the lag time. By that I meant that when the light turns green the first vehicle starts to move fairly quickly (or receive the wrath of a horn blower in vehicle number two).

On the other hand we all have noticed that by the time vehicle number 20 starts to move (that would be me) the light turns red again before I get to the intersection.

Just from my own observation I have timed a lag of from 20 to 30 seconds.

I like this authors point of view on traffic slowdowns on the freeways. In most cases there is no accident, so what the heck happened?

http://www.smartmotorist.com/traffic-and-safety-guideline/traffic-jams.html

10. Jun 5, 2014

Monique

Staff Emeritus
Depends if the gender, I find men spend a lot of time idling at red lights :roll eyes: To answer the second part of your question, especially after midnight in Amsterdam.

11. Jun 5, 2014

I like Serena

Hold on!
If you have found this, how much time did you idle around those red lights? ;)

12. Jun 5, 2014

collinsmark

Here in California, we usually idle on the interstate highways most of the time.

[Actually, I have an electric car. It doesn't idle.]

Last edited: Jun 5, 2014
13. Jun 5, 2014

Monique

Staff Emeritus
All I needed to do was look out the window

14. Jun 28, 2014

anubodh

15. Jun 28, 2014

edward

It is a difficult number to determine because the a number of factors in the equation are unknown. How many vehicles are at idle, for how long, and what size engine are always going to be an educated guess.

Several car builders are coming out with vehicles that stop the engine at idle.
One of the big problems was a need for a battery that could handle the extra load. This has now been accomplished with the new AGM battery.

http://www.edmunds.com/fuel-economy/engine-stop-start-systems-save-fuel-at-low-cost.html

Mercedes stop start system.

Last edited by a moderator: Sep 25, 2014
16. Jun 28, 2014

leroyjenkens

I've been at a redlight in a line so long that the light turns green, then turns red, then turns green again before I actually get to move. I'm actually moving from that first green light. So to actually get through the intersection, it took probably 20 minutes. Something needs to be done about traffic. It almost makes you not want to bother leaving the house in your car. I hate driving mainly because of the people on the road being psychopaths, but also because of traffic. I won't go out some days because the reward of going out doesn't outweigh the grief of driving there and back.

17. Jun 28, 2014

edward

Yep with all of the technology in vehicles one would think that they could teach them to communicate a bit. When that first car stopped at a light starts to move car number 15 needs to know about it.

I wonder what the Google "drives itself" car would do?

18. Jun 28, 2014

AlephZero

I don't quite understamd the problem there. In the UK the standard solution is to look out of the windows to see what the other traffic is doing

But maybe we tend to have smarter lights systems, if only because the average UK traffic density is a lot higher than the average in the US. IIRC there are only a couple of US states that are higher than the UK average over the whole country.

Lights at single intersections that are linked to camera systems rather than road sensors are quite common. If traffic is light and the lights on your road happen to be on red, they will have changed by the time you reach the intersection if no other traffic is there already. You might have to slow down from a 40 limit to 30 or 25 as you approach the intersection, but that wastes less time and fuel than having to stop for no good reason.

In urban areas there are often linked systems of lights over several miles of road, so if you stick to the speed limit you should only hit one red light driving through the entire system.

19. Jun 28, 2014