Unauthorized use of shared use paths, on-street bicycle lanes, and separated bicycle lanes by motorists occurs occasionally. In general, this is a greater issue on shared use paths that extend through independent ROW that may appear to look like roadway or driveway entry points to motorists.

Per the , the NO MOTOR VEHICLES (R5-3) sign can be used to clarify vehicle restrictions.

The routine use of bollards and other similar barriers (e.g., z-gates, fences) placed within the clear width of a bicyclists operating path to restrict motor vehicle traffic is not recommended. Bollards should not be used unless there is a documented history or anticipated high likelihood of unauthorized intrusion by motorists that results in injury. Barriers such as bollards, fences, or other similar devices used to limit access to bikeways create permanent obstacles to bicyclists, which can cause injury. Approaching bicyclists may shield these obstructions from a following bicyclist’s view until a point where the trailing rider does not have sufficient time to react which can contribute to crashes.

A strategy to minimize entry of motorists is to design the shared use path entry point as two sections separated by a conspicuous center island which may include low landscaping. The trail approach to the split should be delineated with solid line pavement markings to guide the path user around the island. Each half section of the path should be no more than 6 ft wide to discourage entry by motorized vehicles while still serving path users.

The center island and landscaping (if provided) should be designed to allow emergency and maintenance vehicles to enter the shared use path, if needed, by straddling the island and passing over the island and/or landscaping. Alternatively, it may be more appropriate to designate emergency and maintenance vehicle access via separate access drives adjacent to trail access points, which can be secured by gates or fencing. Such separate access drives should not be secured only by removeable bollards, as this may encourage potential use by trail users. Where a device to restrict motorists is determined to be necessary, consider the use of flexible or spring-mounted delineators before installing rigid bollards to reduce risk of potential injury to shared use path users. At locations where rigid bollards within the bikeway are determined to be necessary, the following should be provided: