Rails-with-Trails: Lessons Learned

SECTION V: Design

ACTIVE WARNING DEVICES AT TRAIL-RAIL CROSSINGS. An engineering study is recommended for all trail-rail crossings to determine the best combination of active safety devices. Key considerations include train frequency and speed, sight distance, other train operating characteristics, presence of potential obstructions, and volume of trail users.

Active traffic control systems advise trail users of the approach or presence of a train at railroad crossings. Information regarding the appropriate uses, location, and clearance dimensions for active traffic control devices can be found in Part 8 of the MUTCD. In addition, Part 10 of the MUTCD contains specific recommendations for pedestrian and bicycle signals at light rail transit tracks, and should be referred to in cases where trails cross light rail transit corridors. Applicable diagrams from the MUTCD are shown in Figures 5.27-5.30.

FIGURE 5.27 Composite drawing showing clearances for active traffic control devices at highway-rail grade crossings (MUTCD Fig. 8D-1)	FIGURE 5.28 Typical light rail transit flashing light signal assembly for pedestrian crossings (MUTCD Fig. 10D-2)
FIGURE 5.29 Typical pedestrian gate placement behind the sidewalk (MUTCD Fig. 10D-3)	FIGURE 5.30 Typical pedestrian gate placement with pedestrian gate arm (MUTCD Fig. 10D-4)

See Guidance on Traffic Control Devices at Highway-Rail Grade Crossings (FHWA, 2002) for information about selection of traffic control devices. Flashing light signals combined with swing gates (see Figure 5.30) may be needed in cases of high speed transit or freight rail, limited sight distance, multiple tracks, and temporary sight obstructions, such as standing freight cars.

A graphical representation of an RWT culvert under track roadbed. Recommendations are for the culvert to be '2.4m (8ft) min. 4m (12ft) pref' in height. The RWT [trail] width should be '4m (12ft)' wide. A 'Vertical Clearance Sign' at the top of the culvert warning users of culvert maximum height is recommended.

FIGURE 5.31 RWT culvert under tracks

A graphical representation of an RWT track undercrossing in which the tracks cross over the trail with sloped embankments on both sides of the trail. Recommendations are for the underpass to be '2.4m (8ft) min. 4m (12ft) pref' in height. The RWT [trail] width should be '4m (12ft)' wide. A 'Drainage swale' and 'Native plant[s] on embankments' with a 'Slope maximum 2 to 1' exist on both sides of trail which passes underneath the 'Railway.'

FIGURE 5.32 RWT track undercrossing

A graphical representation of an RWT track overcrossing shows a bicyclist traveling along a overcrossing with 'Cyclone Safety Fencing' on each side of the crossing. The height of the railings should be '1.1m (42in)' high. The 'Cyclone Safety Fencing' begins at the top of the railing, extends up and curves over the trail slightly. The width of the trail along the overcrossing should be a minimum of '3m (10ft)' wide with an additional '0.6m (2ft)' clear area on each side.

FIGURE 5.33 RWT track overcrossing

A graphic of a train passing under an RWT track overcrossing shows that the height from trailbed to bottom of the overcrossing should be '7.0m (23ft) Minimum.'

FIGURE 5.34 RWT track overcrossing (meets Amtrak required clearance height for non-electrified track)

Railroad and trail planners should note that the same controls that generally keep a motor vehicle from crossing a track may not keep a pedestrian or bicyclist from proceeding through a crossing. People on foot or bicycle are reluctant to stop at barriers and will often find a way to proceed over, under, or around barricades. Photos of effective treatments in Perth, Australia, are shown on pages 70 and 71 and in Burlington, Vermont, on page 73.

Grade-Separated Trail-Rail Crossings

Grade-separated crossings (overpasses and underpasses) can eliminate conflicts at trail-rail crossings by completely separating the trail user from the active rail line. Refer to the AASHTO Bike Guide for specific design dimensions and lighting requirements for bridges and tunnels. In the case where a bridge or tunnel is constructed, a number of issues should be considered:

EXISTING AND FUTURE RAILROAD OPERATIONS: Bridges and underpasses must be designed to meet the operational needs of the railroad both in present and future conditions. Trail bridges should be constructed to meet required minimum train clearances and the structural requirements of the rail corridor (see Figures 5.31-5.34 and photos on page 80).
SAFETY AND SECURITY OF THE FACILITY: Dark, isolated underpasses that are hidden from public view can attract illegal activity. Underpasses should be designed to be as short as possible to increase the amount of light in the underpass, and to decrease its attractiveness as a hidden area. Adequate lighting is extremely important.
MAINTENANCE: The decision to install a bridge or underpass should be made in full consideration of the additional maintenance these facilities require.

According to the AASHTO Bike Guide, the minimum clear width of the pathway on a bridge or through a tunnel should be the same as the width of the approach path, with an additional 0.6 m (2 ft) clear area on the sides. Therefore, the minimum width of a tunnel or bridge on a 3 m (10 ft) wide trail would be 4.3 m (14 ft). Vertical clearance should be 2.4 m (8 ft) minimum (see Figures 5.31 and 5.32). Larger horizontal and vertical clearances may be needed for certain types of maintenance and emergency vehicles. Future needs for vehicular access should be taken into consideration when designing these structures.

Approach grades for bridges and tunnels on RWTs should follow AASHTO guidelines and typically also must meet ADA Accessibility Guidelines. Again, a greater than five percent grade is not recommended.