18.5.4 Driveways
18.5.4.1 Driveway Crossings of Shoulders and Bicycle Lanes
When on-street shoulders or bicycle lanes cross driveways, their pavement markings should extend through the conflict point as follows:
- Low Volume Driveways (<25 veh/day)- Shoulder and bicycle lane markings should be maintained across driveway with solid white lines. Stop or yield control is optional for the motorists approaching the crossing from private property.
- Medium Volume Driveways (25-500 veh/day)- Bike Crossing Markings should be used (see ); Stop or yield control should be considered for the motorists approaching the crossing from private property.
- High Volume Driveways (>500 veh/day)- Bike Crossing Markings should be used (see ); These driveways may be designed according to the intersection design principles laid out in this chapter. Traffic control should be evaluated with an engineering study.
18.5.4.2 Driveway Crossings of Separated Bicycle Lanes and Sidepaths
For separated bicycle lanes at street level, vertical elements such as flex-posts should be used to control turning motorist speeds into and out of the driveway. They should be placed to define the driveway limits while accommodating the expected turning requirements of the design vehicle. At higher medium to high volume driveways, consideration can be given to developing a raised crossing. See
and
below for details on raised crossings.
For separated bike lanes and sidepaths at sidewalk level, that level should be maintained through the driveway crossing to maintain the raised crossing.
18.5.4.2 Driveway Crossings of Separated Bicycle Lanes and Sidepaths
For separated bicycle lanes at street level, vertical elements such as flex-posts should be used to control turning motorist speeds into and out of the driveway. They should be placed to define the driveway limits while accommodating the expected turning
Figure 18-51: Raised Driveway Crossing
(Refer to the
and
for additional signing and pavement marking guidance.)
For all scenarios, adequate sight distances should be provided to ensure motorists exiting the driveway can see oncoming bicyclists and pedestrians and motorists entering the driveway and can see bicyclists and pedestrians approaching the driveway entrance and stop or yield appropriately. On-street parking, especially if it is serving as the vertical element for a separated bike lane, may need to be restricted on either side of the driveway to achieve desired sight lines.
Designers have two options for evaluating the sight distance. They must consider if motorists will take a two-stage approach and be permitted to block a separated bike lane or sidepath to view approaching motor vehicle traffic, or if there is a need for drivers to exit the driveway in a single movement. The single-stage scenario may be appropriate in locations where the motorist would otherwise block the bike facility for extended periods of time or where bicycle volumes or motorist volumes are anticipated to be high.
As discussed previously,
establishes recommended sight triangles that will generally result in sufficient sight distance for bicyclists.