when it comes to basic street engineering I think safety should be considered from early stages… 2-way streets produce head-on collisions, conflicting vehicles paths produce congenstion… with 1-way street system the absence of these paths reduce risks of collisions and gives you a greater peace of mind…also with 1 way street systems the dangerous left becomes just as easy and as safe as a right one… also intersections are a big problem with 2-way systems, which produces most of today’s accidents, but with 1 way street system there would be no interesecting pathways and so 2 out of 4 corners of every intersection are eliminated so pedestrians will be facing only one stream of turning vehicles…and instead of the 8 turning movement thats now used with the 2-way street system, with one way system you have 2 turnings only… so why arent we thinking of replacing those 2-way systems, that were originally designed for horses, witha balanced 1-way street grid ?
The short answer is that have to build entire towns and cities around that idea alone and that is not most people’s top priority. Plus, people that aren’t very familiar with one-way streets find them hard to navigate. I have no idea if they are safer statistically but those two problems alone will generally kill the idea.
Here in San Jose, Ca. they are in the process of chaning many one-way streets into two way. One of the reasons was that the one way streets are basically Autobauns now. Another being that the residents want a return to a more traditional neighborhood.
“2-way streets produce head-on collisions” is perhaps the single biggest erroneous assumption in the OP. I’m pretty sure that 2-way suburban streets aren’t more dangerous. ::waits for evidence to the contrary::
Yeah. I consider myself a pretty good driver (doesn’t everyone?), and in the twenty years I’ve been driving, I’ve never strayed onto the wrong side of the road (which would be the cause of a two-way street head-on smash), but there have been one or two times I’ve screwed up one way streets.
There’s also the fact that one-way streets likely require driving longer distances, which statistically increases the chance of accidents, that pedestrians will screw up which way to look sometimes instead of automatically looking both ways, and that one-way street systems are frustrating at the best of times (I used to live in one).
Around here, one-way streets seem *more * dangerous.
People unfamiliar with the area will turn the wrong way onto them, which does result in some number of head-on crashes at intersections, plus a whole lot of near-hits, side-swipes and soiled undies.
Pedestrians also are at a bit more risk. If they look left, see no oncoming cars and step out, but cars are coming from the right, they can get hit. I am used to the area and look both ways at all intersections, and I’ve seen more than one car going the wrong way on a one-way street, so I look left, right, up and down. (Believe they call that “keeping your head on a swivel”)
Well constructing a ‘one horse town’ with a system of 1 way streets would be very costly, and also hurt business, as small towns don’t have much traffic to pull in as it is, one way streets would cut that in half. And it would cost a lot more. You might argue that that cost could save lives, but that extra money that you want to use to construct 1 way roads, could be spend on other life saving matters (cancer research, anti-ballistic missile technology, etc.) and could save more lives.
Most of downtown Seattle is all one way streets. Theoretically, one could test to see if certain streets were more inclined to accidents. Of those, probably the top ones would have their status more due to visibility issues, being on a hill, etc. so you would need to individually look at each and remove those which weren’t applicable, first.
Whether such a study has been done, I can’t say. Just saying that it could be done.
When I was a pedestrian, it was the drivers who would only look one way. I can’t count the number of times I’ve stood on the sidewalk along a one-way street, unable to proceed because of a driver exiting a parking lot, stopped across the sidewalk, staring at the oncoming traffic and never looking the other direction. Actually, they didn’t even need to be blocking the sidewalk, because I had a policy of not walking in front of a stopped vehicle without first making eye contact with the driver. But it’s hard to make eye contact when the driver never even glances in your direction because the traffic is coming from the other direction.
IANA traffic safety engineer, but one of my boy scout leaders was. We went down and visited his work once (yes, years and years ago).
One thing he said, which I still remember 30+ years later is that there are always trade offs in traffic safety. He gave an example of stop lights vs. stop signs. People often think that changing from a sign to a light will decrease accidents, but that’s not known. It *will[/] change the type of accidents from more side collisions to more rear ending, IIRC, but the increase, decrease or no change in the total number depends on numerous circumstances.
This is what traffic safety engineers do, and it would be interesting if someone were out there who could give an authoritative answer.
I agree with the post that put forth the idea that 1 way streets promote headons. I’ve never come close to a headon except when I ventured onto a 1 way and I wasn’t going in that direction.
I know this isn’t IMHO, but I can’t help myself from expressing how much loathe one ways.
That is all.
One way streets speed up traffic, but are not safer. Most people do not realize, for example, that you are allowed “free left turns on red” if you are on a one-way and the cross street is one-way to the left. The regular commuters will know of course, but not any of the rest, nor pedestrians. I see a lot of close calls all the time on one ways.
I believe that the main advantage of a one way network of streets, particularly on a grid, is significantly increased traffic capacity.
In traffic engineering, traffic capacity is determined by a complex formula based on lane widths and characterhistics. The basic idea is that a “standard” of a specified width lane will have a capacity of a particular number of passenger car equivalents (PCE) per hour. Trucks of various sizes, buses and other special vehicles are assigned a particular number of PCEs.
The capacity of a lane is adjusted by a number of factors, with significant reductions if it is immediately next to an opposite-flow lane. It is also reduced if it is next to a parking lane or shoulder-less curb. Capacity is also reduced by right-turning vehicles from a through-traffic lane (assuming US not UK alignment), and significantly penalized by left-turning vehicles from a through-traffic lane. Even protected left-turn lanes reduce capacity by requiring a dedicated lane and perhaps protected turn phases in traffic lights.
If two parallel avenues both have two way traffic, they will have significantly less capacity then if the same avenues were each one way. For instance, if each avenue had four traffic lanes and a parking lane on each side, in two way configuration, each lane would have a heavy capacity penalty, with the “right-hand” lane each way being next to a parking lane (and possibly blocked by double-parkers), and the “left-hand” lane next to an opposite-flow lane and clogged with left-turners. On the other hand, if the same avenue is one-way, the outer lanes will be penalized by being next to a parking lane and having a few turners (and a left turn from a one way street is essentially the same as a right turn, from a capacity perspective), and the center lanes will be essentially unrestricted. An additonal advantage is that it is relatively easy to time traffic lights with the traffic on a one way street, but difficult to impossible to do so on a two way street.
So, safety aside, you can get a whole heck of a lot more traffic through a network of one way streets than if those streets were two way.
Here in Bogota, Colombia, there are a lot of one-way streets. Almost every day, someone approaches me going the wrong way on a one-way street. Dangerous, yes! I never see someone going the wrong way on a 2 way street. Safer, yes! On the one-way streets, people often turn left from the right lane and right from the left lane. Dangerous, yes! People here just don’t pay attention to signs. There are many infractions of the law and nobody does anything about them. Maybe in a hundred years things will change.
I’m back in Leon, Mexico on vacation right now, and our house is on a one way street (well, the garage side is on the one way street, anyway). Cars park on both sides of the street, and the minivan we use barely fits. When some idiota comes up the wrong way, you literally have a type of Mexican standoff. Luckily the cars are mostly small here, so the minivan – the bigger of the two – usually wins.
For the OP, though, the criteria should be a bit more defined. In this instance I describe, the one way really is much safer given the conditions and despite the occasional illiterate who can’t read (err, read a friggin’ arrow, that is). But home in Michigan, we have lots and lots and lots of boulevarded streets which are basically one-way on each side of the boulevard. Some of the major streets without boulevards are deathtraps. A lot can go wrong at 50 mph (posted, 60 mph actual) without the median. Michigan turns (look 'em up) save the day, and these 50 mph city streets work well. Consider residential streets, though – is there much necessity for one-way streets given that they’re wide enough to accommodate parking on both sides as well as traffic flowing different directions? Does it matter if they’re suburban streets or downtown New York type of streets? There’s really a LOT to be said when defining the eligible conditions.