Monday, July 20, 2009

The Roundabout Bandwagon

Traffic Roundabouts are becoming a hot topic of infrastructure in the US (see Infrastructurist post, PPS post). Naturally, you would expect Indianapolis, a.k.a. Circle City, a.k.a. Crossroads of America, to be a leader in the circular traffic systems. The symbolic and actual city center is a shared space traffic circle - even the flag (see above) is based on Indy's transportation system.

The monument at the city's center is a shared space (mostly) traffic circle

Traffic can enter from all directions and there are no lane markings but everyone manages well

Indianapolis used a grid layout for the street system (which worked well early in its history), but ended ceding too much ROW to cars and parking for the downtown to remain viable for pedestrians. Later on, Indy unfortunately embraced the raised superhighway with cloverleaf ramp layout. These tactics elevated the rights of drivers (many of whom don't even live or work in the city) over every other citizen and local land-owner. Much of the effort of modern urban planning is attempting to roll back these developments and try to incorporate strategies which allow traffic to flow freely but also protects pedestrians.

Luckily, clever minds in the suburb to the north (Carmel) of the city have decided to take advantage of the modern traffic circle (now known as a roundabout). There are now so many circles in the planning/construction phases that some residents think the traffic planning department is crazy. They have simple roundabouts, regulated circles, dogbone double roundabout highway overpasses, etc. It makes driving a motorcycle a lot more fun, or more exciting if the sweepers haven't been through recently (I lived in Carmel for two years and enjoyed the developments).

This is a dogbone overpass

Wacky, but effective

Traffic now flows through this area much more quickly

Unfortunately, too much signage and lane markings lends a cluttered feeling and causes visual overload for drivers

Carmel also hosts some interesting information on their home page. A link to Kansas State Center for Transportation Research and Training Roundabout page, a link to a flash demonstration showing how to negotiate a roundabout (this should be required viewing for anyone living in Carmel who can't figure out the difference between the yield sign and the stop sign (I know they are the same color, but honestly!)). Finally, a brochure produced in Carmel discussing the reasons for building them and tips for safe driving. Carmel's Roundabouts seem to be good policy. They are still a bit too auto-oriented for my tastes. But they are a great experiment and I hope the Carmel-ites are well served by them.

Satellite image of Clay Terrace north circle

The outdoor shopping area of Clay Terrace has two roundabouts and one pedestrian plaza

The distinctive pavement makes excessive signage unnecessary

The angle of entry and yielding requirements keeps traffic flowing at a slower pace

Pedestrian crossings and median breaks are provided

Here in Irvington, we have three circles of our own (traffic circles - not roundabouts; but I could be mistaken as I have not a great mind for traffic engineering semantics). The two main ones are located on Audubon Road, they were built to link the two sides of the town that grew up across the old National Road. All circles function as traffic control devices, but are not so oppressively auto-oriented.

Satellite image with locations of three traffic circles in Irvington

The North Audubon Circle now is the site for a Methodist church (built 1928). It is the largest of the three circles. Several streets branch off, and it acts as a collector for the arterial of E. Washington Street / US 40 / Historic National Road.

North Audubon Circle

The South Irving Circle is a pocket park with a bust of Washington Irving. The south circle has been recently renovated and hosts outdoor concerts, local gatherings, and plenty of teenagers looking for a place to hang out.

South Irving Circle

Restoring the old brick pavers would really make this area special

The final circle in Irvington is on North Campbell Street, and looks like more of a private development early in the neighborhood history. The central house sitting on it is pretty outstanding, sitting high and proud in the middle of the street. The house is magnificent, but I'm sure it is somewhat similar to living in a goldfish bowl. It's a fun location, and one of the more interesting bits of character that I have found roaming the streets near my house.

Side yard/front yard/back yard... or radial yard?

So there are the three traffic circles in Irvington. Each is different, one hosting a church, one hosting a park, and the other is privately owned. It is easy to contrast the varieties seen in Irvington vs. the modern ones in Carmel or downtown Indy. The experiment with traffic circles has been going on for quite some time in Indianapolis, and I hope the form continues to evolve. One thing for sure is that traffic circles have a great opportunity to act as a transitional element or landmark feature, and modern roundabouts save time, money, and gasoline all day long. I hope that we start taking advantage of it, too.

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Anonymous Anonymous said...

Here's a link for those who want a little more on the "dogbone" :

Keystone drivers celebrate opening of 2 roundabouts

. The image you have has a date of 2007 on it so I thought it would be nice to have something more recent to refer to.

July 25, 2009 3:47 AM  
Blogger Graeme said...

Anonymous - Thanks for the update. It's nice to learn a little about the opening and some of the residents' reactions to cost and time overruns.

July 26, 2009 11:41 AM  

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