The Case Against One-Way Streets

[M II A II R II K]

The Case Against One-Way Streets


Jan 31, 2013

By Eric Jaffe

Read More: http://www.theatlanticcities.com/commute/2013/01/case-against-one-way-streets/4549/

PDF Study: http://www.uctc.net/access/41/access41-2way.pdf

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Cities have long been home to one-way streets because transportation engineers believe they move cars better than two-way streets do. That's largely the case because one-way streets eliminate tough left turns through oncoming traffic. Any way around conflicting lefts, on two-way streets, creates congestion: left-turn lanes take up space, and guarded signals take up time. Vikash Gayah, a civil engineer at Penn State University, isn't so sure about that conventional wisdom. In addition to the aforementioned reasons to convert one-way streets, Gayah believes congestion will improve as well.

- The typical metric of traffic is vehicle flow — which amounts, more or less, to standing on the corner and counting how many cars go by. Flow is high on one-way streets because there's little reason for cars to slow down. But flow doesn't take into account the fact that traveling through one-way street systems often means taking a circuitous route, which adds distance to every trip. "You can move more vehicles through a roadway, but if they have to travel a longer distance, in the end, you have actually fewer people being able to get to their destination and get off the road," says Gayah. Instead, Gayah prefers a metric called "trip-serving capacity," which considers both the flow and the extra travel distance created by a street system.

- So cities looking to improve trip capacity in downtown areas have some options. Smaller cities, with shorter average trip lengths, should be able to reduce congestion by converting one-way streets into two-way streets (with a couple options for left turns). Larger cities, with longer trip distances, should consider a shift to two-way systems that ban left turns entirely. And that's just focusing on traffic. The benefits of switching to two-way streets mentioned at the top of this post only sweeten the deal.

- Even if a city isn't willing to convert its one-way streets quite yet, Gayah's trip-capacity work shows the wisdom of banning left turns at existing two-way intersections. (That's something U.P.S., which doesn't let its drivers turn left, has known for years — and New York appears to be learning this lesson too.) Since such a change carries a very low implementation cost, that's a great place for cities to start. "I think if a city was willing to try that they would see some significant benefits in the long run," he says.

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For very short trips, two-way streets perform about as good or better than one-way streets, whose flow can't compensate for the additional distance. Over longer distances one-way streets start to perform better, but never quite up to the trip capacity of two-way streets with banned left turns (the dotted red line). The beauty of this type of system is that it combines the flow of a one-way street with the directness of a two-way street.

 

[M II A II R II K]

I guess another possibility would be to have parallel 2 way and 1 way streets perhaps.

 

[Rainforest]

One potential advantage of a closely spaced pair of one-way streets: the ability to reserve one lane on each street for transit.

Ottawa uses that option to get the transitway through downtown.

However, Toronto does not seem interested in creating exclusive streetcar ROWs through downtown using the Queen/Richmond and the Adelaide/King pairs.

 

[Admiral Beez]

Manhattan is almost exclusively one way streets and it's both a great city to drive in (I know, that sound odd, but I drive downtown NY and have no issues) and it's a great pedestrian city. One way streets can work.

 

[innsertnamehere]

Manhattan works because of its insanely strict street grid.

 

[calimehtar]

However, Toronto does not seem interested in creating exclusive streetcar ROWs through downtown using the Queen/Richmond and the Adelaide/King pairs.

I think the arguments against one way streets are fair, but this is one thing that is absolutely worth doing.

Outside of the core, Toronto has made ingenious use of one way streets to calm traffic - reversing one way streets make side-streets practically useless for everyone except residents of that street.

There's probably room to have a look at the fringes of the downtown where residential is giving way to condos - between Spadina and University for example - and convert some side streets in that area to 2-way. I suspect that in that area the one way streets are also designed to calm traffic instead of to improve the flow, as in Manhattan, and it may be preventing the area from urbanizing to the extent that it could.

 

[Johnny Au]

Look at Oakwood-Vaughan. It is one-way street galore (especially with the maze within Oakwood, Vaughan, Arlington/Winnett, and Eglinton)!

 

[spider]

This one way street thing has been debated to death, a debate won by the "status quo can't be changed crowd" for all sorts of specious reasons some of which are hilarious. I don't have to drive in New York to know what works, closer to home examples are available. Drive a couple of kilometers through Hamilton, Oshawa or Kitchener-Waterloo and then try the same voyage in Toronto. Case closed.

 

[nfitz]

This one way street thing has been debated to death, a debate won by the "status quo can't be changed crowd" for all sorts of specious reasons some of which are hilarious. I don't have to drive in New York to know what works, closer to home examples are available. Drive a couple of kilometers through Hamilton, Oshawa or Kitchener-Waterloo and then try the same voyage in Toronto. Case closed.

Kitchener? They deemed the 3-decade experiment with one-way streets there a failure, and reverted them back to 2-way operation years ago.

And driving? What about walking and cycling? What about the impact of 1-way streets on local businesses? Surely it's pretty narrow to simply look at the driving aspects.

Though I'm not really sure your point. Toronto has more one-way streets than any of those Ontario places you mentioned.

 

[dunkalunk]

I would say that an argument can be made for use of one-way streets as a traffic-calming measure on local streets, but against one-way streets as a means to increase traffic flow on arterials.

Re: the Kitchener example, the example you may be thinking of may be in Waterloo. I remember at one time, someone calling Bridgeport and Erb streets the world's longest onramp, as that is essentially their existing function. (connecting Uptown Waterloo to the Conestoga Expressway). The opposing one-way streets work incredibly well for auto traffic, but poorly for any other mode.

In the city of Waterloo's cycling master plan and the region's cycling master plan, there are plans for a dedicated, sheltered on one side of Erb Street East (reduction to 2 lanes for auto traffic). It is my hope that Bridgeport Road also sees a formalization of the rightmost lane as a full-time parking lane with bus bump-outs to further increase the traffic calming effects.

 

[Davidackerman]

I would like to add another idea. Make King and Queen one way streets ( opposite directions) and have one streetcar lane run express. This would move traffic and people through downtown and the transit infrastructure is already in place.

so yes I think Toronto's traffic is way too slow for the volume and that's because of no one way streets

 

[Hipster Duck]

I would say that an argument can be made for use of one-way streets as a traffic-calming measure on local streets, but against one-way streets as a means to increase traffic flow on arterials.

I don't know whether this research can make an argument against one-way streets since it's run on a hypothetical model of a city with a perfect grid with imaginary destinations and not a real city in the real world.

I think there are some other merits to one way streets. The first is that, for bicyclists, it seems to be easier to convert one way streets to separated bike lanes because removing one traffic lane out of 4 is much easier than 1 out of 2. The separated bike lanes I know of in the US and Canada, like Maisonneuve in Montreal, Hornby and Dunsmuir in Vancouver, 2nd Ave in NYC, etc. were all carved out of one way streets.

The pedestrian argument hasn't been proven, but my experience suggests that one way streets don't kill vibrancy. Here are a list of some one way streets in other cities in the world: 5th Avenue and Broadway in New York, Ste. Catherine and St. Laurent in Montreal, Boulevard St. Michel in Paris and Bond Street in Montreal. Some of the most vibrant streets in Toronto are one-way, albeit small ones: Yorkville, Cumberland, Baldwin, Augusta.

The problem with assuming that one way streets kill street vibrancy is that one of its hidden assumptions is that people will not walk there because they will be inconvenienced in getting there by car. If they didn't use cars - if they, say, walked there sponatneously from other places - then what would the problem with a road's vehicular traffic pattern be?

 

[ShonTron]

Outside of the core, Toronto has made ingenious use of one way streets to calm traffic - reversing one way streets make side-streets practically useless for everyone except residents of that street.

Ingenious perhaps 30 years ago, but a pain in the butt for cyclists - who I feel should have to "be calmed". At least those cyclists who try to cycle with the sometimes unhelpful rules meant for motorists to follow.

I much prefer the maze of two-way streets found in Vancouver's West Side that give full movement through the grid to pedestrians and cyclists.

 

[doady]

Aren't there are hundreds of one-way streets in the old city of Toronto? Maybe if they were all converted to one-way, it will stop the decline of Toronto's downtown and it can become vibrant place again.

 

[Johnny Au]

Oakwood-Vaughan is full of one-way streets, and is slowly gentrifying themselves. For drivers, it is a maze (hence the large numbers of signs to go to Phil White Arena (which is on Arlington just north of Rushton)). For pedestrians and cyclists, it is very easily navigable.