Driveway Improvements
Consideration for bicyclists’ needs should cover from the trip origin to the destination. A significant proportion of bicycle-motor vehicle crashes occur when either the bicyclist or motorist rides or drives out from a driveway without properly yielding to oncoming traffic. Motorist left turns into driveways and side streets also account for a sizeable portion of crashes involving bicyclists. Thus, the design of connections to the street network has a significant impact on bicyclist safety and access.
Driveway design affects sight distance for both motorists and bicyclists accessing roadways, as well as the speed and perhaps care with which drivers enter or leave the roadway. Right-angle connections are best for visibility of approaching traffic as well as slowing the turning speed for vehicles exiting or entering the roadway. Tighter turn radii at driveways, as well as ramps to sidewalk level, also slow vehicle speeds. Designing Sidewalks and Trails for Access provides more information and design alternatives for driveway/sidewalk crossings.11 Paved driveway aprons of at least 3 m (10 ft) may be desirable for unpaved connections to contain gravel and debris and prevent it from accumulating in the bikeways. Curb cuts should have sufficient flare, however, for bicyclists to complete turns into the driveway or into the nearest lane without ‘swinging wide’ into the adjacent lane. On streets with sidewalks, the walkway should continue at grade across driveways to provide for through pedestrian movement, slow vehicles, and make it clear to motorists and bicyclists that sidewalk users have the right-of-way.
Stop bars, signs, and other measures may be useful at commercial driveways,
but sight distance should not be impaired with too many or improperly-placed
signs. Driveway rights-of-way should also be kept cleared of foliage and other
objects that obscure visibility.
Every driveway connection is a potential conflict point among motorists, bicyclists and pedestrians. Thus, driveway consolidation or other measures should also be considered for arterials and collector roads. See the Access Management countermeasure for more discussion.
Purpose
- Provide good visibility for motorists and bicyclists accessing the roadway.
- Slow motor vehicles entering/exiting the roadway and establish pedestrian right-of-way.
- Reduce the chances of a bicycle-only fall or turning error when bicycles enter or leave the roadway.
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Considerations
- Local landscape ordinances and other driveway guidelines may be needed to establish clear zones for driveway rights-of-way, and to maintain sight distance and roadway surfaces.
- Driveway crossings of sidewalk corridors should be wide enough to provide a level pedestrian crossing and a suitable ramp to the street.
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Estimated Cost
No additional costs when incorporated into original plan and construction.
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Case Studies
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