A well-designed roundabout manages traffic flow much better than the four-way stop or traffic lights beloved in North America. I suggest looking on Google Earth at successful, varied designs on the roads in some English New Towns, especially Stevenage and Peterborough north of London. There are other varieties in Europe - I have driven in Spain where the exits from and entrances to freeways are handled by a bridge or underpass across the freeway, and local traffic is distributed to and from slip roads onto small slow-speed roundabouts. Land is used efficiently in such circumstances. If you would like to see some thrilling driving, skillfully using roundabouts, look at the YouTube videos of Chris Martin, an EMS car driver in the north-of-London area including Stevenage. (Remember, he sits on the 'wrong' side of the car, and drives on the 'wrong' side of the road for N. American viewers).
I read and liked your piece on roundabouts. While you make excellent points about reducing the risk of serious accidents, for cyclists who are instructed by road markings to orbit around the edges of the roundabout, there seems to be a risk that roundabout-leaving drivers won't remember that there's an outer bike lane ring.
That's one area where N. American roundabouts fail. In the Stevenage examples I mention above (or below, depending on how Substack organises the comments....) you can clearly see the pedestrian and cycle traffic is grade separated from the roads (underpasses, mostly).
Whenever intersection-conversion-to-roundabout comes up, my colleagues are quick to point out that roundabouts often take up more space in the actual intersection than a signalized intersection with the same number of approach lanes. I LOVE that you highlight how roundabout corridors can achieve the same throughput as their signalized counterparts with LESS lanes, narrower right-of-way, etc.
If we want to change the road-building industry, we have to start speaking their language and beating them at their own game. Thanks for making the case that, even if transportation engineers are committed to the same (bad) metrics that got us our suburban transportation systems in the first place, there are solutions and systems that work better for *everyone*.
Andy - I’ve been wanting to write something very similar for years. Of course the additional benefit is roadways are sized based on intersection throughput, so if you have smarter intersections you can also road diet the primary portion of the corridor. The opportunities to reclaim land just grows and grows. It’s my unconfirmed belief that about 80% of all major suburban intersections could be roundabouts.
Fun fact - they’re also much easier on municipal budgets since they don’t have expensive electronics that need to be maintained and replaced every so many years.
Kevin, write it! :) Years ago one of my roundabout mentors had a large plot of an arterial entering, obliterating, and exiting a rural town. After doing the traffic analysis to show *just the same* level of service as the existing corridor, he had landscape architects sketch over the aerial to scale what a roundabout corridor would look like. Their minds were blown at the reclaimed land and the DOT said yeah, no.
That's a typical suburban corridor?? 😱 Makes my skin crawl.
Roundabouts take up very little space that's why we have them everywhere here, because space is at a premium (also since too much of it is devoted to road transport and car storage)
Great piece, Andy--I hope DPW/DOT will start doing the right thing soon. A site right outside my neighborhood was ideal for a roundabout and even the people you might expect to be NIMBY's were in favor of it but DPW said it took up too much land that would have to be acquired from adjacent properties. Baloney!
Your point that corridors with turn lanes end up widening the corridor beyond just the intersection is so rarely stated. Thank you for pointing this out!
A well-designed roundabout manages traffic flow much better than the four-way stop or traffic lights beloved in North America. I suggest looking on Google Earth at successful, varied designs on the roads in some English New Towns, especially Stevenage and Peterborough north of London. There are other varieties in Europe - I have driven in Spain where the exits from and entrances to freeways are handled by a bridge or underpass across the freeway, and local traffic is distributed to and from slip roads onto small slow-speed roundabouts. Land is used efficiently in such circumstances. If you would like to see some thrilling driving, skillfully using roundabouts, look at the YouTube videos of Chris Martin, an EMS car driver in the north-of-London area including Stevenage. (Remember, he sits on the 'wrong' side of the car, and drives on the 'wrong' side of the road for N. American viewers).
I read and liked your piece on roundabouts. While you make excellent points about reducing the risk of serious accidents, for cyclists who are instructed by road markings to orbit around the edges of the roundabout, there seems to be a risk that roundabout-leaving drivers won't remember that there's an outer bike lane ring.
That's one area where N. American roundabouts fail. In the Stevenage examples I mention above (or below, depending on how Substack organises the comments....) you can clearly see the pedestrian and cycle traffic is grade separated from the roads (underpasses, mostly).
Whenever intersection-conversion-to-roundabout comes up, my colleagues are quick to point out that roundabouts often take up more space in the actual intersection than a signalized intersection with the same number of approach lanes. I LOVE that you highlight how roundabout corridors can achieve the same throughput as their signalized counterparts with LESS lanes, narrower right-of-way, etc.
If we want to change the road-building industry, we have to start speaking their language and beating them at their own game. Thanks for making the case that, even if transportation engineers are committed to the same (bad) metrics that got us our suburban transportation systems in the first place, there are solutions and systems that work better for *everyone*.
Genius, as always, Andy. Thank you!
Thanks Connie :)
Andy - I’ve been wanting to write something very similar for years. Of course the additional benefit is roadways are sized based on intersection throughput, so if you have smarter intersections you can also road diet the primary portion of the corridor. The opportunities to reclaim land just grows and grows. It’s my unconfirmed belief that about 80% of all major suburban intersections could be roundabouts.
Fun fact - they’re also much easier on municipal budgets since they don’t have expensive electronics that need to be maintained and replaced every so many years.
Kevin, write it! :) Years ago one of my roundabout mentors had a large plot of an arterial entering, obliterating, and exiting a rural town. After doing the traffic analysis to show *just the same* level of service as the existing corridor, he had landscape architects sketch over the aerial to scale what a roundabout corridor would look like. Their minds were blown at the reclaimed land and the DOT said yeah, no.
Denial ain't just a river in Egypt, as they say.
OK, I'll try to move that piece up the chain since you threw down a major gauntlet.
That's a typical suburban corridor?? 😱 Makes my skin crawl.
Roundabouts take up very little space that's why we have them everywhere here, because space is at a premium (also since too much of it is devoted to road transport and car storage)
Great piece, Andy--I hope DPW/DOT will start doing the right thing soon. A site right outside my neighborhood was ideal for a roundabout and even the people you might expect to be NIMBY's were in favor of it but DPW said it took up too much land that would have to be acquired from adjacent properties. Baloney!
Your point that corridors with turn lanes end up widening the corridor beyond just the intersection is so rarely stated. Thank you for pointing this out!
This is well said! Thanks Andy!