Are there any circumstances in which a motor vehicle can legally use a bicycle lane?
Yes! The most common might be when a motor vehicle is entering or leaving the main travel lane to enter or exit the roadway. The usual placement of the bike lane along the right side of the travel lane makes that necessary.
Another situation is when a motorist is preparing to make a right turn and is required by law to move to the right-hand curb or edge of the roadway. On curb and gutter roadways, the bicycle lane is a part of the roadway. Bicycle lanes on paved shoulders are a different topic entirely, and won’t be covered in this question.
s. 316.151 – Required Position and Method of Turning at Intersections
(1) The driver of a vehicle intending to turn at an intersection shall do so as follows:
(a) Right turn – Both the approach for a right turn and a right turn shall be made as close as practicable to the right-hand curb or edge of the roadway.
Proper striping of bicycle lanes will change from solid lines to dashed lines well before the intersection, indicating that right-turning vehicles will move right and bicyclists who are proceeding straight through the intersection may enter the travel lane to improve visibility and avoid conflict with right-turning vehicles. An intersection is an “unsafe condition” that is an exception to the “keep right” rules. Motorists must insure that the lane is clear before changing lanes into the bicycle lane, and cyclists must insure it is safe before moving into the travel lane.
The bike lanes are not always striped as they should be, and motorists do not always look before changing lanes, so all precautions should be taken by a cyclist approaching an intersection, whether in a bike lane or not.