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How To Build Roads To Control How Fast You Drive
An anonymous reader writes "They're the holy grail of transportation engineering: streets and highways specifically designed to encourage automobilists to drive less quickly, reducing the rates of passenger fatalities and generally encouraging a safer urban environment. And now new research shows that, if built right, they just might work. A new study out of the University of Connecticut suggests that minor reductions in vehicle speed are possible through changes in the street environment. Through the use of roadside parking, tighter building setbacks, and more commercial land uses, road designers can make drivers subconsciously drive more slowly." All of that is gonna work a lot better than my strategy of placing car-sized holes covered with twigs and branches randomly every half mile or so down the interstates.
Good grief. From TFA:
And:
Who would have thought that by reducing a driver's visibility, the driver would go slower to give themselves time to react to surprises? You? You in the back? Are you some kind of smartass? The Connecticut Department of Transportation studied this for four years. There's no way you could have arrived at the same conclusion so quickly!
This study was useful in determining how much people slowed down -- quantifying it at about 10% -- but sweeping on to claims like, "reducing the rates of passenger fatalities and generally encouraging a safer urban environment" is silly. Streets packed with parked cars, pedestrians, nearby buildings, et. al. are generally more dangerous precisely because clear lines-of-sight are cut off. Sane drivers know this, reduce their speed, and then -- making wild hand-waving guesses, here -- wind up with about the same overall level of "dangerousness" as when driving on uncluttered roadways.
1) You can make the road look more dangerous, e.g. with optical illusions to make it look narrower
2) You can make the road actually and obviously more dangerous, e.g. reducing sight lines and adding on-street parking
Number 2 works, but it doesn't increase safety. Number 1 works... for a while. My concern with #1 is that drivers will realize they are being fooled, and start speeding up again. That's OK, except they may then interpret the real situation that the illusion was imitating as an illusion, and fail to take it into account, resulting in a net decrease in safety.
speed bumps also greatly slow down emergency vehicles. If you have ever been in an ambulance going over speed bumps you will curse the name of whoever came up with such a painful idea
the preceding post was not spell checked... suck it.
As a former employee of an international road transportation company, we studied the exact same thing.
Interesting fact. When someone is driving in a place they don't know, they drive slower. You can duplicate the effect by making changes to a known environment, like this study does by adding cars to the roadside. Second interesting fact? Once the changes become 'known', speeds return to what they were previously. I notice this part is somehow absent in the claims that "the lower speeds make things safer."
If I was from the University of Connecticut, I'd be embarrassed to be releasing this study.
It is my experience that congested roadways are considerably more dangerous than ones with free flowing traffic, and when you slow down traffic you also increase congestion. It may be the case that free flowing traffic has more deadly accidents (due to the higher speeds involved) than accidents on congested roads, but the congested roads have a much much higher rate of accidents.
But as a person who actually drives, it always bugs me when I see these studies that invariably conclude that the worse you make driving, the safer it is. First it was cities with no street signs, and pointless traffic circles, and zigzags in the road, or just traffic lights programmed to jam up traffic as much as possible. Now we're going to remove the safety margins between vehicles and magically improve safety.
Maybe I'm nuts, but it seems like city planners would prefer it if just nobody drove at all and just took mass transit everywhere, which would be wonderful if they actually had usable mass transit outside of the city center.
I read the internet for the articles.
But outside of interstates and restricted-access roadways, roads are used by more than just automobile drivers.
Buses are stopping and going, pedestrians are walking to work or going shopping, people are parking, deliveries are being made, and cyclists and motorcyclists are going about their daily business.
There is a benefit for making streets usable for everyone -- it increases the livability of a community, reduces urban sprawl (and the associated financial and environmental costs), and allows the elderly and disable to live more independent lives.
Now before someone starts ranting about how they pay tax on gas and thus roads should only be for cars, the gax tax does not come anywhere close to funding roads in the US -- a large portion of the money needed to maintain and build roadways comes from property taxes and the general fund.
Actually -the study was originally done by European regulators, who found that as drivers were isolated from external stimuli, they drove faster. So for example a town with no traffic lights had a lot lower average speed for cars - than in towns with traffic lights, stop signs etc. When the signs are taken out, the responsibility directly shifts to the driver, and while it is a bit more tiring, the results are fascinating.
http://www.spiegel.de/international/spiegel/0,1518,448747,00.html
Read it.
First of all, "holy grail of transportation engineering"?? Bullshit. The goal of transportation engineering should be to achieve the best balance of maximized capacity, efficiency, and safety. You can always make roads safer by slowing things down - until you try to make them safer by causing congestion.. and the congestion causes frustrated and aggressive driving. The study basically says to throw more shit in the way of drivers to slow things down.. That's because it's creating an unsafe environment.. and drivers naturally try to compensate for it.
Here in Florida, the transportation engineers have decided that old people react slower. Therefore, all traffic lights change slower.. So that causes inattentive driving since people can be waiting as much as 5 minutes between lights. Then, people are very slow to start proceeding through the intersection once lights turn green - partly because desperate drivers run all the yellow lights because they have to wait another 5 minutes between lights. My argument would be that traffic rules should not change to accomodate for people unable to follow the rules. Chicago's lights change quickly at an intersection..
Also, our political wanker of a governor (Charlie Christ) decided he did not like the 'move over law' because he said it promoted speeding. So, people are free to sit in the left lane of major highways going under the speed limit while others try to get around them. Florida interstates are a clusterfuck.. Nobody moves over.. So you have a clump of cars bumper to bumper for a mile.. and then a mile of highway that hardly has anyone on it.. I would argue it would be safer to have an actual passing lane and allow people to spread out.
Cars today have more horsepower, more traction, better safety, and more braking power than cars 20-30 years ago.. Yet, our speed limits have decreased.. Why?
Traffic is an absolute mess.. and the idea that 'slower is safer' is contributing to that mess.
--- We need more Ron Paul!
That's what punishment really is for. It doesn't make sense to make the road less safe for everyone, merely to slow down the few people going well over speed limits. For those, you can fine, suspend their license, or even jail.
The Portugese system goes further and makes other drivers angry with you for speeding.
I think the Portuguese system is the future. Note that it shames you in front of other drivers, but that it also slows you as a penalty for speeding. People will naturally adopt the behavior that gets them where they are going fastest. If you make 'speeding' the slower option, people will just naturally drive safer.
I would be surprised if assholes were deterred by narrower lanes. Anyone on a residential road who feels that *they* are safe at 90 mph isn't paying attention to rational queues.
How about designing roads that are safer to drive fast on.
Fast is good if it's safe
That is really cute. I would just stop caring and go through the red.
You can't handle the truth.
Around here, we have a law that says the state (as in US state) sets the speed limits on all roads unless a waiver is given to a locality (city or county) to override the speed limit that would ordinarily apply to a given road.
I'm sure the purpose is both uniformity (so everyone "knows" how fast to drive on unfamiliar or unposted roads) and to prevent municipalities from changing speed limits arbitrarily (speed traps, etc).
The side effect to this in the larger urban areas is that in response to heavy traffic, people seek out residential through streets as means around the major arterial streets, which are clogged. The people living on those streets hate the traffic and the speeding that goes with it, so the residents are able to petition the council to get speedbumps installed on their streets.
IMHO these suck. One, they don't really slow or divert that much traffic. Usually you see people driving the speed limit and then braking hard at the speed bumps and then accelerating hard to get back to their speed limits. While I sympathize with the people living on those streets, they ARE through streets that belong to everyone who pays taxes, not private roads for the benefit of the residents -- you only ever see speedbumps in upscale residential areas.
I also think they are illegal usurpation of the state speed limits -- you can't drive the legal speed limit on the street without damage to your vehicle and/or creating a dangerous situation flying off the bumps.
This is really idiotic, what is it, the 'survival of the slowest' law? Here is what I see on roads in Baden Baden, Germany. There are many narrow mountain roads here, you'd think people would slow down, many drive very quickly right through the turns, the twists, whatever. The autobahn is amazing, no matter how fast you are going, there will be someone zooming right past you. In the city there are limits that are a bit lower than what I am used to from North America, but those are normally very short stretches of the road where they don't want you to make too much noise, people really mostly follow the speed limits very closely. There is a very well developed public transit system here, and this is not including the railroads. There are many roundabouts and they are wonderful, you have to slow down but often you can go through it without any stop, and it is an intersection, there are no lights there. Seems intuitive and friendly enough, however in the city core the streets are often so narrow between two very close buildings that you just can't go fast, but you don't expect to. But this would not work for a large city, it would be completely stuck, there are only a few tens of thousands of people living here. It would not work for Toronto for example (which was just named as the city with the worst traffic ever, it takes people more than 80 minutes on average to commute both ways and the public transportation is not growing.)
No no no, if you want people to slow down, you are doing it wrong. You need to get people into public transportation system, then there will be fewer people driving and there would be more space on the road, yes people would go faster, but there would be fewer fatalities still, if fewer people are behind the wheel.
You can't handle the truth.
There are significant differences in the use of speed limits in the US versus Europe. US speed limits are slower with a larger amount of enforcement judgement granted the police. The purpose of that approach is to create a large body of willing speeders to generate revenue off of. Drivers tend to disregard posted limits when they are unreasonable. My experience in Europe is that speed limits are more reasonable with less tolerance of speeding. Their attitude seems to be maintaining safe speeds rather than profits, at least as compared to the US.
With that pervasive government corruption in mind, I'm not sure that european approaches will be that interesting for the US. Portable shame machines are, in fact, used in the US but frequently they are to trick radar detector drivers into ignoring warnings so that police get a clear shot. They get paid for by insurance companies who profit from rate hikes when drivers get tickets. The US speed limit policy is all about revenue generation, not safety. That is true of all US traffic enforcement.
One last thing, US drivers tend not to care what other drivers think.
That sounds like a beautiful idea.
I had a similar idea for parking lots, but I never tried to fund it.
Pneumatic speed bumps. If you speed, they pump up, if not, no bump...
Another idea I had was to raise the speed limit by 10mph/kph after 8pm.
This gives semi-trucks a solid reason to drive off-hours, since they will do anything to make more time and hence money faster.
This would free up bandwidth for commuters.
And of course, my biggest idea to date is:
Free Speed Limit Database.
Thanks for sharing that Portugal thing. Abrigado.
Require car manufactures to have speedometers that are accurate (and easily calibrateable) and I will support your proposal. Simply getting new tires can chuck the speedometer by 5MPH, nevermind other factors.
upon the advice of my lawyer, i have no sig at this time
The trick is not to make slower drivers, the trick is to make SAFER drivers. Slower drivers are not always safer drivers.
1) Set accurate speed limits so people will actually follow them. It is ridiculous that "following traffic" means having to break the law.
2) Mandate *better* and *harder* driver license tests. In the US it is all too easy for someone to get a driving license with little or no training. (seriously; check out this test: "Drive in a straight line, drive backwards in a straight line, parallel park, do a 3 point U-turn", and the kicker is, many states only require you to do TWO of the above. And if you fail the test, you can pay the fee and take it again, and in the mean time despite failing, you're allowed to continue driving with your permit.
3) Have the police start enforcing SAFE driving concerns. Enforce laws about people driving in the wrong lane, driving while on the cell phone, driving with improper equipment. Yes, I know, speeding tickets are great revenue, but stop enforcing only the speeding laws, especially when you're not making anyone any safer you're just picking up revenue from some unlucky sob (or more likely these days lining the pockets of a traffic lawyer).
If the focus was on safety, we could raise speed limits and increase traffic flow and reduce congestion.
disclaimer: I catch a lot of crap for driving a "sporty" car, but I focus all my attention on safe driving. driving should be a cooperative adventure, not a competitive sport. Take all the a-holes and distracted drivers off the road and we could all enjoy our commute and weekend drives a lot more. =) Just telling people to slow down, or trying to find ways to force them to slow down won't really change anything, other than perhaps an increase in speeding tickets. =/
But the fact is, you are making the roads more dangerous! How can this be a good thing?
Because drivers are more careful, and rarely careless, when conditions are dangerous. People being careless is usually what kills.
Alaska sees dangerous, icy roads 2/3 of the year, yet our over-all accident and death rate is lower than the national average. Shouldn't it be the case that the nice, grippy streets of the lower 48 would be much safer?
We also tend to drive individually and do less carpooling and the like because destinations are so far apart. So again, dangerous roads seem on the surface to mean people drive more carefully, for a net reduction in accidents and loss of life.
Security is mostly a superstition... Avoiding danger is no safer in the long run than outright exposure. - Helen Keller