For background on the SLM (Shared Lane Markings, a.k.a. sharrows) on the phoenix-side, see here, and more pictures here. That first link has an explanation as to why this bridge is an important and useful link for bicyclists.
The Guadalupe Road bridge over I-10 itself has a vertical wall and no sidewalk along its south edge, and a curb and sidewalk along its north. There are no sidewalks either east or west of the bridge whatsoever.
Bridge deck dimensions (measured from Google maps, usually accurate to within maybe a foot): South vertical wall to North curbface = 34 feet; edge line to edge line = 24 feet.
The street is posted 25mph max speed limit. I don’t know the volume but it seems quite low.
The street to the east of the bridge has a fairly steep downhill grade. To the west, it’s closer to level; in other words, the topography of the area must be that it’s higher on the west (closer to the mountains) than on the east.
The trouble with fake bike lanes
The bridge itself, and the roads on both sides leading up to and away from the bridge have a solid white line; this line is an edge line (EL) and not a Bike Lane (BL) stripe.
Note that there is very little usable width for any bicyclist to the right of the stripe, due to 1) debris, 2) the gutter pan seam on the asphalt section, and 3) the two foot wide drain grate. Bicyclists really ought not ride here. For the recommended position on where to ride, see where-to-ride-on-the-road — hint in a narrow lane, ride near the middle of it to avoid both the edgehazards as noted above, and to discourge too-close passing.
This stripe is an edge line and should not be placed here, it is an urban road, and is not warranted.
When I asked why, exactly, there was an EL there, here is the answer I eventually got “…we believe the best approach for the Department (ADOT) will be to not restripe the EL and allow the stripe to fade over time rather than obliterating”. So apparently it was not warranted, and/or doesn’t and never belonged there — yes, I am reading between the lines.
So what should be done?
If a dedicated bicycle facility is absolutely necessary, on the east side of the bridge, because of the downhill grade, a REAL bike lane could be easily created westbound (and would actually be useful, because it’s uphill), with SLMs marked on the easbound (downhill) side. In other words there’s enough room for one BL, but not two. This would, of course, require ADOT to do a BL, and has been observed before, “ADOT doesn’t do bike lanes”.
To the west, i’m not sure what would work, or even be useful — this is a rather short stretch, only about 500′; whereas the east section is more like 1000′ and has a more significant grade.
Sun Circle Trail
A potential complicating factor is this is along the route of the Sun Circle Trail, and was supposed to (circa 2005??) have had an independent/parallel trail bridge (mixed use, including equestrians). The bridge was never built but the bridge supports are in place, and rumor has it the money has resurfaced circa 2016.
Parts of this trail were built in ~ 2013, see here along Calle Guadalupe through town, this is about 1500′ east of the bridge. It’s a crushed-granite sort of affair adjacent to the road but set back like 50′ with some pretty landscaping.
#fakebikelane #adot #edgehazard