The Shrine

The "fundamental rule" of traffic: building new roads just makes people drive more

The basic idea being that driving is generally the easiest way to get to anywhere. It requires little to no physical exertion and is incredibly cheap (after the initial cost of the car). Most places in the US and Canada are built around the automobile as opposed to walking/biking/transit. Therefore, people will generally drive as much as they can with the only limitation being road capacity. Road capacity is only run up against during peak driving times (rush hour). People know roads are bad during these times so they stay off of them if they have a choice. The natural reaction of people stuck in traffic is "build more roads" or "add more lanes". This is self defeating as once those new roads or lanes are opened, the choice drivers will then fill them to capacity again and you're back to square one. The authors advocate Congestion Pricing as a better solution to traffic jams. They think the best way to reduce congestion is to put a price on use of the roads and vary the price based on the demand. Interestingly enough, adding new transit lines doesn't seem to help much with congestion as choice drivers quickly take the place of commuters switching to transit.

Thoughts?

You WANT more tollbooths? Not my favorite idea of a way to reduce congestion.

I remember seeing that on a SimCity hint book saying if you build more roads, more cars just magically appear on the road so you got to build rail instead, and I think that's true even in real life.

That said, building more roads in where you have high traffic is still going to help. If a million cars go through a particular area (say, to work) and you only have half of that capacity, it'd be pretty hard to price your way out of it as opposed to just build twice the roads. Sure even more people will drive when you do that but it's not like you'll really be able to produce another million cars out of thin air. A lot of the congestion area I see usually is related to losing a lane and people all trying to change lane at once and having an extra lane there would help a lot more than just the capacity alone would indicate.

MORE roads rarely help because I promise that most drivers rarely take side routes. I have seen side routes so underutilized that I wonder why they were built, but probably it's because no one really knew all this stuff we're discussing yet.

WIDER roads and mass transit can help a lot.

I think the reason roads are congested are because they're "free" to use. People have this idea that they pay for roads with their gas taxes but that hasn't been true for decades. Gas taxes only cover a fraction of the cost of building & maintaining roads in the US. Most of the funding comes from general taxation and borrowing (unsustainable).

The solution? Usage fees of some sort. This can be tolls, increased fuel taxes or even vehicle miles traveled (VMT) taxes. I'd think tolling would be most effective because the correlation with driving is most obvious. Fuel taxes will have a problem going forward as drivers shift away from purely gas & diesel powered vehicles. There are also some privacy concerns with the VMT tax.

Mana, for fuck's sake, why do you want to build more tollbooths? Yes, that will reduce road usage, because people don't like to pay for basic access to OTHER PLACES, but it seems like a bad "solution" to me.

I got some toll roads nearby and they're always nearly empty so it sure doesn't look like it's used very much. I know there's congestion pricing on some lanes too but again if the traffic is simply overloaded you're not going to just magically get the road to uncongest just because you charge $20 for the lane that isn't congested. I don't think it's necessarily about wider roads, it's more like you can't have a section of heavy traffic that's suddenly missing one or two lanes because you always get the guy who try to squeeze in at the last moment that slows down everyone.

Toolbooths suck for one very important reason: They prevent the full and unfettered use of the public facility being built.

They stop traffic, make people feel harassed, add 10-15 minutes or longer to travel times - half an hour if there's a long toll line.

Hospitals don't say "There's a long wait at the ER, so please pay $5-10 or leave the facility", because that would be immoral, hurtful, and insane, and a hazard to public health if an injured/sick person leaves the facility and dies or breaks public property in a haze of pain. Police stations don't charge you to see an officer - because stopping criminality benefits everyone. The fire department will charge you for rescuing your house from a fire, flood, or what-have-you, but only AFTER the event, and at an appropriate juncture, and with respect to the potential costs to your life and family; their first priority is stopping disastrous public safety failures or fires that can spread to other homes or destroy a citizen's livelihood.

Public services are supposed to be public and free, at least as much as possible, for a reason: they are public services. Roads shouldn't charge you to drive on them. They are created out of public money for the public good.

You want to help stop congestion, Mana - and it's a worthy goal to be sure - then advocate that all new freeways be five lanes, that all major city roads be three, and that all one-lane streets be wide enough to allow U-turns and basic car maneuvers. (All suggestions mean the number of lanes PER direction.)

It is my theory, based on what I have read from city planners and from my own experiences over the years, that severe congestion is MOSTLY a function of two things : 1) high population density and 2) inadequate road space.

The first is an unavoidable consequence of human success as of 2015. The second is very easy to deal with, WITH appropriate city planning. It's when you get cities laying down on the job or building two-lane streets for ten-story buildings or such that things really get bad.

I'm with Don on this one, mass transit options.

There's little benefit to toll roads. The major problem - lower income drivers would have an additional expense burden on them; it would greatly impact their day to day lives. It'd be akin to taxing groceries. Not to mention the inconvenience of toll roads just slows everything down tremendously. Third, it would be anti-transport and passenger business.

I don't think that toll roads are an option everywhere but for roads that get congested and are already built out and toll roads (& congestion pricing) is a superior way to solve the issue than road expansion.

Ultimately I think this will be a non-issue when self-driving cars come on the scene over the next few decades. They'll be able to maximize the existing space and synchronize with each other to keep traffic moving smoothly even during rush hour.

I remember seeing that on a SimCity hint book saying if you build more roads, more cars just magically appear on the road so you got to build rail instead, and I think that's true even in real life.

I gotta love the SimCity reference. I played the hell out of SimCity 2000 when I was in high school.

The other problem with your "toll booths on congested roads" idea, Mana, is that toll roads BY THEIR NATURE are a form of congestion. You have to slow to a stop, pay, wait for the inevitable clogs if someone forgot the toll, pay the toll operators or risk catastrophic gridlock from a car that can't pay, etc.

The newer toll road just reads something from your car that you can pre register to pay, or pay later so you won't slow down. Still, it's like the carpool lane. Just because you got one lane that's going at the normal speed while everyone else is coming to a crawl doesn't mean you solve anything at the global level and it doesn't matter if that particular lane requires you to have 3 guys in a car or pay $20. Self driving cars will definitely help since they wouldn't be trying to cut people off or squeeze in a lane in the last moment but urban planning matters too, and most of that is because they didn't have the foresight to have enough roads when people are exiting/entering en masse.