There are many instances where trails will pass beneath vehicular bridges to create a grade separated path. Vertical clearance is critical, and for longer underpasses lighting may be needed.
- Maintain 8’-0” minimum vertical clearance or higher as required by municipal/partner needs.
- 2% max trail cross slope.
- The typical 3’-0” minimum level shoulder should be maintained on either side of trail.
- Incorporate guardrail or other safety barrier between trail and lower slope, where lower slope is in excess of 3:1, stabilized with hard material or along a wall with a fall of greater than 2’-6”.
- Drainage from overpass above should be routed away from trail. Water should never fall directly on trail.
- Should be designed to withstand potential flooding. Fencing should be cable rail system where likely to flood.
- Design should consider flood debris removal and sediment removal, allowing maintenance equipment access as required by maintenance partner. Design should also consider maintenance requirements for overpass.
STANDARD CROSS SECTION
COMPONENTS: Click below for more information on each component.