Emissions per mile still go down. It is always more efficient per mile to drive at 40 mph than 60 mph, even if it takes longer.
Idling is negliable compared to the energy lost to air resistance.
Start-stop is a bit complicated, but it can be eliminated with hybrid vehicles and better trained drivers who understand how to drive in high traffic situations.
Also, people generally limit their trips by time, not by distance. This is related to induced demand, but if you increase the average car speed on a route, then those cars will just drive farther. If you live in a place with traffic and spend 15 minutes to get to the grocery store, then you’ll only go to grocery stores nearby. If you don’t have traffic, then you might drive the extra 5 miles to get to the cheaper grocery store on the other side of town. So the average engine run time does not go down when you reduce traffic.
Again, hybrid cars are actually more efficient in that kind of traffic than at 40+ mph, and those sorts of traffic waves are usually caused by bad drivers not knowing how to react to road congestion.
But sure, if people are regularly driving in stop and go traffic in a fully gas car, then I guess the pollution is worse than 40 mph. Adding new lanes would massively increase pollution due to the induced demand. There are more effective and cheaper ways to reduce traffic and pollution than to double the capacity of the road.
Emissions per mile still go down. It is always more efficient per mile to drive at 40 mph than 60 mph, even if it takes longer.
Idling is negliable compared to the energy lost to air resistance.
Start-stop is a bit complicated, but it can be eliminated with hybrid vehicles and better trained drivers who understand how to drive in high traffic situations.
Also, people generally limit their trips by time, not by distance. This is related to induced demand, but if you increase the average car speed on a route, then those cars will just drive farther. If you live in a place with traffic and spend 15 minutes to get to the grocery store, then you’ll only go to grocery stores nearby. If you don’t have traffic, then you might drive the extra 5 miles to get to the cheaper grocery store on the other side of town. So the average engine run time does not go down when you reduce traffic.
Traffic jams don’t go 40mph. They go up to 15mph and then back down to close to zero and back up to 15mph. That’s absolutely horrible for emissions.
Again, hybrid cars are actually more efficient in that kind of traffic than at 40+ mph, and those sorts of traffic waves are usually caused by bad drivers not knowing how to react to road congestion.
But sure, if people are regularly driving in stop and go traffic in a fully gas car, then I guess the pollution is worse than 40 mph. Adding new lanes would massively increase pollution due to the induced demand. There are more effective and cheaper ways to reduce traffic and pollution than to double the capacity of the road.
LOL, you ninja edited your post to add that part about start-stop and then acted like it’s my fault for not seeing it.