Eli5 How are carpool lanes supposed to help traffic? It seems like having another lane open to everyone would make things better?

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I live in Los Angeles, and we have some of the worst traffic in the country. I’ve seen that one reason for carpool lanes is to help traffic congestion, but I don’t understand since it seems traffic could be a lot better if we could all use every lane.

Why do we still use carpool lanes? Wouldn’t it drastically help our traffic to open all lanes?

In: 406

72 Answers

Anonymous 0 Comments

Nothing too dramatic, but once on Miami I ducked into a funnel to evade a lookout. About half way through, I notice an enforcer entering the tunnel from then side I’m headed for. I figured a random enforcer is easier to deal with than a lookout, so I keep heading that way. You guessed it: another lookout. Needless to say everything went to unrecoverable shit.

Anonymous 0 Comments

There’s usually fewer cars in the carpool lane, so people using it get a better commute. The people carpooling are in one car instead of 2-5 cars, so there’s fewer cars in all lanes now, and everyone else gets a slightly better commute.

Anonymous 0 Comments

As much as anything it’s for the busses. Busses need to stay on schedule and getting caught in gridlock isn’t condusive to that. The fact that they allow HOV drivers in that lane is secondary.

Anonymous 0 Comments

I think it’s to reward people for taking a car together.

Thought being if two people are in one car then they are not driving two different cars.

Anonymous 0 Comments

The technical term is [induced demand](https://en.wikipedia.org/wiki/Induced_demand). More lanes = more and worse traffic.

Closely related is [Braess’s paradox](https://en.wikipedia.org/wiki/Braess%27s_paradox). Adding capacity actually slows down traffic.

The better solution would be to instead close the non-carpool lanes and put rail lines in their place. But this is America. Land of individualism. Nobody really wants it to be better. They just want more lanes of worse bumper-to-bumper traffic.

[Please stop adding more lanes to busy highways—it doesn’t help](https://arstechnica.com/cars/2021/08/please-stop-adding-more-lanes-to-busy-highways-it-doesnt-help/)

Anonymous 0 Comments

Look up induced demand. Adding lanes does not solve traffic and usually makes things worse in the long run . Look at cities where they just constantly add lanes instead of promoting public transit, they have horrid traffic with massive highways. LA is one of the cities where they constantly add more lanes, does it help?

Examples of such are the Katy freeway and the 401 in Canada.

Ps I realize I misread the post but my response is still valid in the sense that you want to promote more efficient lane usage before letting people go ham on them

Anonymous 0 Comments

By reducing cars on the road overall if people car pool. To incentivize them to do, they get a faster lane to use.

Anonymous 0 Comments

In some places there are formal or informal systems in which drivers pick up people without cars in order to use the carpool lane and get to work faster. Generally however they just don’t succeed in taking cars off the road.

Anonymous 0 Comments

If you reduce the number of vehicles on the road, you reduce the amount of traffic.

As an incentive to try and stop single-rider vehicles, the car pool lanes allow multiple-rider vehicles.

Anonymous 0 Comments

Nothing too dramatic, but once on Miami I ducked into a funnel to evade a lookout. About half way through, I notice an enforcer entering the tunnel from then side I’m headed for. I figured a random enforcer is easier to deal with than a lookout, so I keep heading that way. You guessed it: another lookout. Needless to say everything went to unrecoverable shit.