There are numerous potential solutions that can be explored to mitigate inefficiencies and risks of current LRT-crossing technologies. It is important to compare and analyze new and current technologies to achieve the best possible solution.
Enhanced Audible and Visual Warning System
Audible warning systems using Bluetooth technology and video camera detection can provide more effective warnings to pedestrians and cyclists at an LRT crossing in locations where crossing gates are not installed18. The video camera detection can be used to detect an LRT approaching, road vehicles, pedestrians accidents and near-misses to trigger the warning19. Speakers emit a warning notification to indicate that a train will be passing shortly. The warnings are verbal pre-recorded messages. Aside from the audible warnings, pedestrians will be able to receive push notifications on their cell phones advising to put away their devices as they approach a crossing. The push notification is based on the geolocation proximity of the passenger in regards to the crossing location20. The technology can be further developed to allow warning to be sent out when a train is arriving shortly for additional protection.
There are also visual warning systems available, such as embedded LED lights which light up alongside the LRT crossing at the intersection, mimicking a crossing gate while using a virtual light barrier instead21 of a physical one. This technology has been used in a few systems in the world. While not yet widely adopted, it could be a further improvement in achieving an “urban style design” by eliminating physical barriers.
The advanced audible and visual warning systems can add an extra layer of protection, hence reducing the potential system downtime caused by accidents. However, it must be understood that such technologies still may not optimize any traffic flow or LRT operation. In addition, Calibration, operation in inclement weather, or operation in 40 below temperatures and maintenance affect effectiveness and costs of these solutions.
With lightweight LRV22, the lighter mass of the LRV allows for better acceleration and deceleration. The enhanced deceleration increases the capability of the LRV to stop in case of emergencies near at-grade crossings. A lighter LRV also decreases power consumption for acceleration, while the improved acceleration and deceleration performance allows for quicker clearance of an intersection. A major problem with LRT crossing gates is the long gate time. With faster acceleration and deceleration of LRVs, the gate time could be effectively reduced, resulting in less traffic wait time. A similar effect can be achieved at TSP intersections as a shorter LRT phase time is required. However, it should be noted that the reduction of the LRT crossing time based on such technology could be limited, since other factors such as LRT operations, safety concerns including coordination with surrounding vehicles, bikes and pedestrians, and passenger comfort may limit the maximum acceleration and deceleration rates. Pedestrians and cyclists may also need to be more aware of the surroundings at grade crossings, where an enhanced audible and visual warning system mentioned in the previous section could be helpful under these conditions.
Emerging automation technologies for rapid transit
If the origin-destination (OD) information of all vehicles on the network can be collected proactively and communicated among each other, the resulting optimization could be even more effective. This is where adding emerging automation technologies to TSP come into play.
Train automation technology has been proven in the railway industry for decades such as Communication Based Train Control (CBTC) or Europe Train Control System (ETCS Level 4). However, the challenge is the communication between train and road vehicles. Emerging automation technologies can include two main categories: Connected Vehicles23 and Autonomous Vehicles24. The connected vehicle technology consists of data communications between connected vehicles and LRVs. Having the ability for connected vehicles and LRVs to communicate allows for more efficient management of traffic flow because traffic signal controllers’ detection capabilities will not be limited to the immediate area around the intersection. This technology will be most effective when the majority of vehicles are connected. Some North American equipment suppliers have indicated that mass production of the vehicle-to-vehicle communication components can start approximately 2.5 to 3 years after certain regulations are established25. An LRT system also is a highly beneficial platform to pilot connected vehicle technologies due to the controlled environment of the LRVs.
Autonomous vehicles can also further improve the efficiency and operation of an LRT system when they are used in conjunction with connected vehicle technologies. The Society of Automotive Engineers (SAE) defines six levels of automation, classified from no automation (level 0) to full automation (level 5)26, and it is predicted that a mass deployment of fully autonomous (level 3-5) will be achieved in the 2030s or 2040s27. Any emergency situations that happen at level grade crossings can be communicated by the vehicles to the LRV through connected vehicle technology to allow for coordinated action between vehicles and improved safety. The technology could potentially enhance the TSP technology, and may even further eliminate the need for most signals and gates if fully implemented, reducing the cost of crossings.
It is important for transit agencies and governments to be aware of the predicted timelines for these technologies and prepare for their arrival. Although these technologies are still being developed and tested today, it is not advised that one should simply sit and wait for it to happen while the congestion continues to build up. Instead, infrastructure upgrades and other solutions for LRT crossings need to be planned and designed carefully in the mean time to prepare for a future of greater efficiency throughout its life-span.
On the other hand, considering that these technologies would reduce the need for major infrastructure upgrade or protection equipment (similar to the TSP solution), it is beneficial when considering an “urban style design”, as it does not divide communities. However, extra attention needs to be drawn to pedestrian/active mode user safety due to a lack of physical protection equipment.
A combination of various advanced technologies may further improve efficiency, such as applying an “advanced audible and visual warning system” to address safety concerns and using lightweight LRVs to reduce the LRT phase time. In all cases, it is essential and necessary to apply simulation tools to evaluate the overall performance of an intersection28. The figure below demonstrates an ideal scenario where advanced technologies can be applied to an LRT level crossing.