Monday, September 10, 2012

When the political pressure to paint stripes trumps logic and engineering best practice


 Andy Cline posted the picture below on his Carbon Trace site in Springfield, MO, showing some really bad traffic engineering just foisted on bicyclists. This bike lane egregiously violates AASHTO guidelines by including the gutter pan in the bike lane space. This forces cyclists to ride on the gutter pan seam while being squeezed into a very poor ("gutter bunny") lane position, encouraging motorists to think there is enough space for a cyclist and motorist to be riding side by side. This will undoubtedly be sold as making cycling "safer" and "more attractive" and making Springfield more "bicycle-friendly".

Cherry St. in Springfield, MO. The AASHTO minimum bike lane width is 5 feet to the curb face, with a minimum of 3 feet of smooth pavement to the left of the gutterpan seam**
 Photo showing actual dimensions here.

The keyword here is blackwhite. Like so many Newspeak words, this word has two mutually contradictory meanings. Applied to an opponent, it means the habit of impudently claiming that black is white, in contradiction of the plain facts. Applied to a Party member, it means a loyal willingness to say that black is white when Party discipline demands this. But it means also the ability to believe that black is white, and more, to know that black is white, and to forget that one has ever believed the contrary. This demands a continuous alteration of the past, made possible by the system of thought which really embraces all the rest, and which is known in Newspeak as doublethink. Doublethink is basically the power of holding two contradictory beliefs in one’s mind simultaneously, and accepting both of them.
— Part II, Chapter IX — The Theory and Practice of Oligarchical Collectivism” (George Orwell--1984)

The job of any PE or PTOE should be "first, do no harm". Unless we take an Orwellian view of bicycling infrastructure, believing that designs incongruous with bicycling best practice become advisable if you "hold two contradictory beliefs...simultaneously".  What I find acridly humorous is that the point of the sharrow lines up with the hazardous gutter pan lip. Fall down and get hurt---here.

Thankfully, I don't think the picture above would ever make it past the laugh test here.  But unfortunate results can creep in even when accepted designs are installed without adequate analysis of specific conditions. Three recent crashes on Diamond between Orange/Sandia and West Road this year come to mind, as bike lanes were added to areas rife with right turning traffic, hence right hooks. Another example of the law of unintended consequences.

**19.2 Bicycle Lane Widths and Construction Standards
Bicycle lanes serve the needs of all types of cyclists in urban and suburban areas, providing them with their own travel lane on the street surface. The minimum width of a bike lane should be 1.5 meters (5 feet) against a curb or adjacent to a parking lane. On streets where the bike lane is adjacent to the curb and the curb includes a 1-foot to 2-foot gutter pan, bike lanes should be a minimum of 4 feet wide (width does not include the gutter pan, since bicyclists are typically unable to use this space). http://safety.fhwa.dot.gov/PED_BIKE/univcourse/pdf/swless19.pdf





3 comments:

Steve A said...

Not to mention the flying saucer on top of the cyclist's head...

Ian Brett Cooper said...

"**19.2 Bicycle Lane Widths and Construction Standards
Bicycle lanes serve the needs of all types of cyclists in urban and suburban areas"

Wait... I'm pretty sure I'm a 'type of cyclist' and I avoid bike lanes like the plague. They certainly don't serve my needs - in fact, they prevent me from meeting my needs, because in order to cycle in the way I prefer, I need a road without a bike lane.

Anonymous said...

These bike lanes are more common than you think; DE has quite a few "bike lanes" like this A few have been widened, but even these are striped to the curb when a right turn lane starts. You might also be impressed with the sharrows in Baltimore installed in the left tire track of parked cars.

These facilities actually make sense if you view them as tools to keep bicyclists from interfering with motor traffic. Both engineers and advocates see these lanes as an improvement - advocates because it gives bicyclists a place to ride (they tell me), engineers because they remove bicycles from traffic lanes and free up the road for motor traffic. (Use mandatory in MD, not yet in DE or PA.)

Angelo