A friend posted this photo on facebook.
The placement of the shared-lane markings shown, centered in the lane, is good. The shared-lane marking is a standard treatment in the Manual on Uniform Traffic Control Devices (MUTCD), as is green paint for use in bike lanes. As of this writing, the green paint underlay of a shared-lane marking is in experimental status. Issues which might oppose it: the expense of the added paint; does it actually affect behavior; the “cry wolf” effect of use of green paint in increasing numbers of types of installations.
Traffic control devices — signs, signals and markings — are supposed to express a consistent symbolic language. In North America and in countries influenced by North American practice:
- Rectangular signs with a white background are regulatory signs — that is, they indicate what the law requires. Examples are speed limit signs, no-parking signs, no turn on red signs.
- Yellow, diamond-shaped signs are warning signs, indicating a potential hazard or the need for caution.
- Green signs with white text are directional signs, or wayfinding signs. Examples are street-name signs, the signs preceding off-ramps on interstate highways and bike route signs.
- And so on — blue background: emergency routes or services; brown background: parkland information; orange: construction zones.
- Similarly for paint on the road, yellow is for a line or area which drivers are not supposed to cross; blue, for handicap parking; green, for use in bike lane conflict zones; white, for most other road markings.
Of all of the colors for road paint, green, being the newest, is the one least standardized, and there is a tendency to use it indiscriminately, — so road language becomes road slang, with inconsistent and changing meanings.
The experimental process leading to inclusion of new signs, symbols and markings in the MUTCD is intended to refine, and define, their use, and to forestall the confusion which results from indiscriminate use.
This process has sometimes been criticized for being too cumbersome, but on the other hand, consistency matters!