My code is compiling so I have a moment...
Rachel: Bike Lanes, yes absolutely. That is a physical space that people are attentive to - cyclists and the motoring public. It's marked on the roadway and for whatever reason drivers respect it.
But signs in pittsburgh don't cut ice. On a limited access highway, the signs are big, bright and simple. There are no other items to draw your attention away from the signs. However, in an urban environment like Pittsburgh there are passive and active features situated within a dense, confined space which very easily draw your attention away from a street sign. If it's not a green light or a stop sign, then they don't stand out and are often obscured.
We aren't on a grid where all directions are X blocks here and Y blocks there; where all streets are the same width; where all signs and signals are in the same place; all traffic lanes are marked.
We are not Seattle or Portland or Chicago - far from it. I'd say we're most like new york, south of canal street. Where roadways have varied widths from block to block; change from one-way to two-way and back to one-way; intersect at weird angles. And lots of commuters and out-of-towners unfamiliar with the environment by day with fewer local folk on the streets at night.
As far as enforcement, Portland has some pretty steep fines for cyclists and motorists don't they? Folks learn real fast how to properly operate their vehicles when you hit them in the wallet it seems.
Just my $0.02