Raise the Hammer

"Bike-bus lanes are travel lanes restricted to buses, bicycles, and (usually) vehicles turning right. The lane is separated from general purpose lanes by a solid white line, and designated by signs and painted legends. This configuration requires bicyclists and buses to pass one another in "leapfrog" fashion. Cities employing shared bike-bus lanes include Tucson, AZ; Madison, WI; Toronto, Ontario; Vancouver, BC; and Philadelphia, PA.

Shared vs. Separate Lanes
On a busy arterial street with conventional bike lanes, buses frequently block the bike lane at bus stops. Bicyclists may also be squeezed between the door zone of parked cars on the right and adjacent traffic on the left. A shared lane eliminates these issues, but may introduce new hazards. However, many bicyclists feel the shared bike-bus lane functions better than a conventional bike lane because bus traffic tends to be relatively light, bus drivers are professionally trained to coexist with bicyclists, and buses can merge partway into the adjacent lane to overtake a bicyclist. Nevertheless, many local traffic departments are reluctant to allow bicyclists access to bus-only lanes. This effectively disenfranchises bicyclists on streets where dedicated bus lanes have been deployed, but denying bicyclists access to them.

In some cities, bicycle lanes are provided to the left of dedicated bus lanes (see photo). This introduces turning conflicts where buses turn left across the bike lane, and bicyclists turn right across the bus lane, and motorists turn right across both.

Safety Studies
A reportedly suppressed study by Transport for London leaked to the London Telegraph indicates that on two corridors where bicycles and motorized cycles were allowed in bus lanes, bicyclist crashes were reduced 44%.
Bike-bus lanes have been used in French and German cities. Paris and Bordeaux have shared lane networks of 118 and 40km, respectively. According to the German Cycling Federation, the Federal Ministry of Transportation reports bicycles are safer using bus lanes, and bus operations are not negatively affected by this arrangement. The Ministry states that, where traffic speeds exceed 30 mph, the width of the lane should be at least 4 meters (13 feet) to allow bicyclists to overtake a bus without entering an adjacent lane. Narrower widths, typically 3.0 meters (10.5 - 11.5 feet) are acceptable in lower speed environments (20mph or less)."

http://streetswiki.wikispaces.com/Bike-Bus+lanes