Use of Channelization with Gates

At many crossings, drivers can cross the centerline pavement marking and drive around a gate with little difficulty. The number of crossing gate violations can be reduced by restricting driver access to the opposing lanes. Highway authorities have implemented various median separation devices, which have shown a significant reduction in the number of vehicle violations at crossing gates. (30) Various styles of median treatments include barrier wall systems, wide raised medians, and mountable raised curb systems. In addition to discouraging crossing gate evasion, such treatments may be used to restrict left-turns across the median to and from driveways or minor streets adjacent to the crossing thus reducing conflicting vehicular turning movements in the crossing vicinity. The benefits of installing channelization should be considered along with possible adverse effects on local access and circulation as well as the potential for a road user to strike the barrier. Medians and traffic channelizing devices need to be kept out of the path of turning vehicles to avoid being 73struck. The median should be designed to allow vehicles to make left turns or U-turns through the median where appropriate, based on engineering judgment and evaluation. It should be noted that median treatments meeting the requirements of Appendix A of 49 CFR Part 222 are considered supplemental safety measures by FRA for use in a quiet zone (see Quiet Zones).(5)

Barrier Wall Systems

Concrete barrier walls and guardrails prevent drivers from crossing into opposing lanes throughout the length of the installation. In this sense, they are the most effective deterrent to crossing gate violations; however, the road should be wide enough to accept the width of the barrier and the appropriate end treatment. Sight restrictions for vehicles with low driver eye heights and any special needs for emergency vehicles to make a U-turn maneuver should be considered (but not for circumventing the traffic control devices at the crossing). To increase the effectiveness of barrier wall systems, they should extend from the crossing to a length of 100 feet.

Wide Raised Medians

Curbed medians typically range in width from 4 to 16 feet, although wider medians may be present along divided highways. Although they do not present a true barrier, wide medians can be nearly as effective because a driver would have significant difficulty attempting to drive across to the opposing lanes. The impediment becomes more formidable as the width of the median increases. Drawbacks to implementing wide, raised medians include the availability of sufficient ROW and the maintenance of surface and/or landscape. Additions such as trees, flowers, and other vegetation higher than 3 feet above the roadway can restrict drivers’ views of approaching trains. Maintenance can be expensive, depending on the treatment of the median. Limitation of access can cause property owner complaints, particularly for businesses.

Non-Mountable (Non-Traversable) Curb Islands

Non-mountable curb islands are typically 6 to 9 inches in height and at least 2 feet wide and may have flexible, reflectorized tubular delineators or vertical panels. Drivers have significant difficulty attempting to violate these types of islands because the 6 ‑ to 9‑inch heights cannot be easily mounted and crossed. Some disadvantages should be considered. The road must be wide enough to accommodate a 2-foot median. The increased crash potential should be evaluated. AASHTO recommends that special attention be given to high visibility if such a narrow device is used in higher-speed (greater than 40 mph) environments. (22) Care should be taken to assure that an errant vehicle cannot bottom ‑out and protrude into the oncoming traffic lane. Sight restrictions for low driver eye heights should be considered if tubular delineators or vertical panels are installed. Access requirements should be fully evaluated, particularly allowing emergency vehicles to cross opposing lanes (but not for circumventing the traffic control devices at the crossing). Paint and reflective beads should be applied to the curb for night visibility . 74The State of Illinois has developed a standard that uses a combination of mountable and non- mountable curbs to provide a wide, raised median with escape zones both in the median, as well as to the shoulder (see Figure 36). This treatment is intended to allow vehicles trapped on the tracks due to queued traffic to maneuver from the crossing to a safe area in the median or on the shoulder. Figure 36. Example of Combination of Mountable and Non-Mountable Curbs from Illinois Department of Transportation Source: Illinois Department of Transportation, Bureau of Local Roads and Streets Manual, Illinois DOT, Revised June 2018, Mountable Raised Curb Systems. 75Mountable Raised Curb Systems (Traffic Separators) Mountable raised curb systems or “traffic separators,” with flexible tubular delineators or vertical panels present drivers with a visual impediment to crossing to the opposing traffic lane (see Figure 37). The curbs are no more than 6 inches in height, less than 12 inches in width, and built with a rounded design to create minimal deflection upon impact. When used together, the mountable raised median and tubular markers or vertical panels discourage passage. These systems are designed to allow emergency vehicles to cross opposing lanes (but not to circumvent the traffic control devices at the crossing). Usually, such a system can be placed on existing roads without the need to widen them. Figure 37. Example of a Traffic Separator Source: USDOT, Federal Railroad Administration, Research Results 10-03 (Washington, DC, June 2010). Because mountable curbs are intended to allow emergency vehicles to cross and are designed to deflect errant vehicles, they also are the easiest of all the barriers and separators to violate. Large, formidable tubular delineators or vertical panels will inhibit most drivers. Care should be taken to ensure that the system can withstand normal traffic conditions and that retroreflective surfaces are maintained in good condition for night-time visibility. Additional guidance is found in the MUTCD Section 3B.23. These mountable raised curb systems have proven effective and are relatively inexpensive compared to treatments which require roadway reconstruction. (30) These traffic separators are installed along the centerline of roadways, in most cases extending approximately 70 to 100 feet from the crossing. They prevent motorists from crossing lanes to “run around” activated crossing gates. The separators consist of prefabricated, mountable islands made of a composite material. Attached to the islands are vertical panels or tubular delineators with retroreflective surfaces for better visibility at night. The vertical panels or tubular delineator are flexible, yet securely anchored allowing them to return to their original positions if struck by a vehicle.