- 110 mph or less: Grade crossings are permitted. States and railroads cooperate to determine the needed warning devices, including passive crossbucks, flashing lights, two quadrant gates (close only 'entering' lanes of road), long gate arms, median barriers, and various combinations. Lights and/or gates are activated by circuits wired to the track (track circuits).
- 110-125 mph: FRA permits crossings only if an "impenetrable barrier" blocks highway traffic when train approaches.
- Above 125 mph, no crossings will be permitted.
Strategies to reduce risk at high-speed rail grade crossings range from eliminating crossings whenever possible, to the use of advanced train control systems.
Advance train control systems will monitor and communicate train locations and speeds and will stop the train if the crossing is not clear.
Four quadrant gates reduce risk significantly when used in conjunction with existing technologies.
There are a number of Demonstration Systems currently being developed or are under testing for instance:
- Michigan ITCS Demonstration : includes upgrade of 57 public grade crossings to provide constant warning time and improved or eliminated 21 private grade crossings. System linking crossings to locomotives via the positive train control system has been in daily revenue service operation since April 2001.
- The North Carolina’s Sealed Corridor assessment is another significant project underway, which applies innovative, low cost techniques to significantly reduce or eliminate incidents of highway vehicles bypassing crossing gates, thereby virtually eliminating grade crossing incidents. Further information about the Sealed Corridor and North Carolina's efforts can be found on the State's web page www.bytrain.org.
Other innovative concepts are being sought for integrated demonstration and assessment for efficacy on revenue corridors through the National Academy of Sciences Innovations Deserving Exploratory Analysis (IDEA) Program and through broad agency announcements (BAA).
For more on demonstration systems, evaluation tools and evolving technologies, research and solutions such as the use of impenetrable barriers please see e-Library.