General Road and Highway Discussion

[danbrotherston]

Given that it's a one lane roundabout, it is going to be orders of magnitude safer than the monstrosities that the region builds, but that doesn't change the fact that in the middle of a residential neighbourhood they build an intersection designed to facilitate high speed traffic at the expense of pedestrian and cyclist safety---this is why people drive.

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I cannot measure the new traffic circle because I have no Google Maps satelite photo of it yet but I'm guessing it's going to be at least as big as the new ones on Laurelwood Dr., and that's leaving aside the different geometry (what I'm calling a turbo roundabout) which enables drivers to pass through it even faster.

Thanks. What I found on “turbo” roundabouts seemed to imply that they are multi-lane roundabouts:

http://www.turboroundabout.com/turbo-roundabout.html

I think that’s a different usage.

I agree that in the middle of a residential neighbourhood is not a place where we need an oversized roundabout. It’s perfectly fine if large trucks have to navigate carefully to get through — leave the wide-open spaces to the main highways.

I’ll have to get out to the new road to see what it’s like. It doesn’t yet appear on Google Maps, and of course it isn’t visible in the overhead photography yet so I’m not even clear on its exact route.

The thought just occurred to me that the repressive zoning rules don’t carry over into traffic design. One could imagine a world in which industrial areas were designed with large truck-friendly vehicle infrastructure while residential areas were designed with narrow pedestrian-friendly streets; but instead (almost) everything is designed for fast vehicle traffic.

Yeah, they absolutely do imply a multi-lane roundabout, which is why I am so surprised to see aspects of one (specifically parts of the geometry) here...to be honest, I'm assuming a definition which is at best, not complete.

This roundabout is massive, even when you look at large trucks using it[1]. You can see in the twitter image, a large tractor trailer pulling a flat bed trailer navigating the circle with two to three times the vehicle width to spare. The geometry does not serve to enable vehicles of that size, it serves to expediate them, as well as increase the speed of drivers.

[1] The design vehicle in a neighbourhood should NOT be a giant truck. And it should only be a large bus on bus routes. There is the concept of a control vehicle, i.e., a large vehicle that may use an intersection occasionally, but is expected to navigate the intersection outside of the normal path of vehicles, i.e., using all lanes or even jumping a curb. The Laurelwood and Beavercreek roundabout would handle a large transport truck in this way--at least going straight. So trucks could still navigate the intersection, but in a slow and careful manner. It's also worth considering the network as well, if a route isn't a truck route and there is another access that already accomodates large vehicles, then an intersection doesn't need to be designed to accomodate them.

But in all cases, this roundabout is too large even for giant trucks.