Wednesday, October 19, 2011

Diamond and Canyon, the Saga Continues

Wearing my bicyclist and LCI hats, I met with Ann Laurent (Asst. County Administrator) and Nancy Talley (County Traffic Manager) yesterday at Canyon and Diamond at 11:30 to bat around some ideas for a redesign of the bike lane/former right turn lane on northbound Diamond at Canyon.  County Staff have been looking at a couple of redesigns and I suggested one as well out of the National Association of City Transportation Officials guidebook, just released. The idea I suggested is of a combined shared right turn/bike lane, but with clear markings consistent with better roadway positioning. That specific design can be found here and I pasted a picture from the NACTO guide below.

Mind you, the NACTO is not the same as MUTCD, i.e., MUTCD is the engineer's bible and NACTO is not. We will have to find a MUTCD consistent solution, I suspect.

We saw at least three instances of two cars trying to turn right synchronously while we were standing there, i.e., one car using the bike lane and one car using the regular lane, and both trying to squeeze into Canyon headed east at the same time and having to jockey around each other. Crazy stuff. 

Example of a shared turn/bike lane, Eugene, OR
From the NACTO Guide
The wheels are turning on this and that's as far as I will go. Stay tuned, and meanwhile, "let's be careful out there". Regardless of the design, its your grey matter that keeps you safe, not the stripes on the roadway.


JerryM said...

I believe a well marked, shared bike/car turn lane would be a perfect solution at this location.


Steve A said...

While I haven't considered all ramifications of the shared lane like the one in the photo, it does suggest that a few good ideas come from Oregon amongst all the idiocy. Hmm. That doesn't mean I'm about ready to start rooting for the Ducks!

Khal said...

We will have to be a bit ingenious at that location.

MikeOnBike said...

One MUTCD option is to drop the bike lane stripe a couple hundred feet before the intersection, leaving a plain wide outside lane. Less is more?

The other option is to dash the left stripe and drop the right stripe before the intersection. See Part 9 figure 9C-6. I'd do the full 200 feet.

MikeOnBike said...

Here's a direct link to the figure:

I'm specifically thinking of the right side middle of the figure which indicates "...200 feet of dotted line if ... heavy right turn volume".

That's basically the same idea as the Oregon example, but with less paint, fewer signs, and no reason to re-invent something that's already standard.

Jon said...

I *mostly* like the combined lane, with an exception I'll come back to later. It could be emphasized with a "carpet sharrow" treatment...I think it was SLC that did some shared-lanes with the sharrow zone in a continuous green carpet, like the merge conflict zone lanes.

The exception is the left-hook possibility if southbound motorists are confused by through cyclists in the right turn lane. Coming home on Tuesday I had to brake pretty hard--not quite panic stop--to avoid t-boning someone turning left. I was in the through lane, not the bike lane, so my visibility was even better than someone would have in a combined lane. Mind, I was going 35MPH and the motorist had "seniors 2012" painted across the windshield so this was a somewhat atypical situation for bike speed and driver line-of-sight. A carpet treatment through the intersection may help.

Khal said...

My worry about 9c-06 without a right guide mark is that cyclists who don't know any better will be hugging the right side by the curb and will still get cut off by right turning traffic. The advantage of showing the bike lane through the length of the approach on the left side of the turn lane is that it encourages better bicyclist positioning, i.e., it positions the cyclist to control the lane.

Without that lane control,I'd prefer no bike lane marking at all but instead a sharrow in the rightmost of the straight thru lanes. County was not too keen on that since there are bike lanes on either side of this treatment, leading to potential for weaving and confusion. Confusion we already have!

Jon said...

Saw a scrape-and-paint crew out there about noon today; the left edge line of the bike lane is gone. Looking forward to good things!