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I took a transportation engineering class a while back and one bit of knowledge that stuck with me is tolls are the only effective traffic relief mechanisms for
by ronbenton 10mo ago
I took a transportation engineering class a while back and one bit of knowledge that stuck with me is tolls are the only effective traffic relief mechanisms for a roadway. Other mechanisms like adding lanes just invite more cars and traffic is not relieved. I never checked whether this was true, but sounded reasonable.
- bwhiting2356 10mo agoAdding lanes may not cut congestion in the long term, but it can increase throughput and overall utility by moving more people and goods.
- ronbenton 10mo agoI don't doubt it. It is quite a while ago so I don't fully recall the talk that my professor gave, but I don't believe he intended to mean adding lanes was useless, just that they didn't help with congestion of the particular roadway
- bluGill 10mo agoIf adding lanes doesn't help you didn't add enough. People live in a city to do things and you need to enable that by preventing congestion. i don't know how to afford the 50 more lanes that most cities need though. I suggest better transit.
- loglog 10mo agoRemoving parts of the city to add more lanes will also help decreasing demand - it's a win-win!
- cmovq 10mo ago[flagged]
- ronbenton 10mo agohow do you see that something is downvoted? I don't see points on any comments but my own
- JumpCrisscross 10mo ago> how do you see that something is downvoted? You can’t directly. If the comment goes negative, it get greyed out. (In many cases, people are complaining about a comment they like not being the top comment.) Either way, complaining about the voting is against the guidelines and thus flaggable. That causes your comment to get marked as flagged.
- simonra 10mo agoLook up «Braess's paradox», more throughput when removing capacity is long established (century +) in systems with simplistic greedy agents like humans
- CarVac 10mo agoRoad throughput doesn't solve congestion when road throughput isn't the issue. They are trying to widen the NJ Turnpike but the congestion isn't because 6 lanes aren't enough, the congestion is because the three Hudson crossings into Manhattan cannot ingest 6 lanes worth of traffic.
- array_key_first 10mo agoEach additional lane has less and less impact because of lane switching. Ultimately, you can still only enter or exit on the left or right, regardless of if you have 100 lanes. And having people move across 100 lanes to exit is much slower than moving across one or two.
- expedition32 10mo agoBut you run into the risk that people don't use your new expensive toll road and you're left with a big pile of debt... That is the problem with them in the Netherlands. Building and maintaining roads is so frighteningly expensive that you can't price them to even cover the cost!
- ronbenton 10mo agoI think perhaps my professor was talking about adding tolls explicitly as a traffic congestion relief mechanism rather than a way to recoup cost of maintaining the roadway
- black_puppydog 10mo agoSo you mean if we dont socialize the up-front cost plus the ongoing externalities, roads aren't economically sensible choice? That seems less like a problem and more like the beginning of a nice reflection...
- DaSHacka 10mo agoNo form of transportation would be at that point
- throwatdem12311 10mo agoIt’s just supply and demand. Of course just creating more supply when the cost to the consumer is basically 0 will just juice the demand to fit the new capacity. Tale as old as time.
- MangoToupe 10mo agoHave you considered fuel rationing?
- throwaway2037 10mo ago> Other mechanisms like adding lanes just invite more cars and traffic is not relieved. I have been seeing this argument for 30 years, and, yet, rich cities in the US (and Canada) continue to add more lanes. My guess: It is just so politically positive to build more lanes that politicians continue to approve them. Why doesn't this happen as much in other rich countries?
- kj4211cash 10mo agoFormer transportation engineering prof here. This is exactly right. And for many transportation engineers, it's a reason to support toll lanes and to oppose adding (other) lanes. But I agree with some of the other commenters here, that adding lanes supports greater movement of people and goods and, separately, that toll lanes are regressive and come with plenty of (other) issues that are often ignored. My personal take on this is that toll lanes and congestion charging are the most effective methods we know for relieving congestion BUT that they are an incredibly difficult sell politically and maybe for good reason; maybe their issue are worse than the congestion they mitigate.
- ronbenton 10mo agoThank you for your perspective. May I ask why you don’t still teach? I have always been fascinated by the idea of being a professor but never had the dedication to get a phd
- kj4211cash 10mo agoI had a 3 year appointment overseas and could only get similar offers for my next job and only in places I didn't really want to live. Also my father was a professor and, to be honest, it was hard not to notice how much worse the job had gotten. Started to seem like twice the work for 10 or 20 percent of the salary and impact, as compared to tech. Also I was starting to have misgivings about transportation engineering as a field. So I guess just a lot. But I do miss the freedom to research what I thought was important. And teaching too. Honestly, academic jobs are more appealing to me now, in terms of lifestyle fit, than they were previously. I still apply for academic jobs occasionally but lately haven't gotten close to getting one. Don't get me started on the academic job market or application process. Ha!