Passenger rail services operating at grade in street rights of way forego many of the efficiencies inherent in steel rail freight train operation. Frequent starting and stopping, acceleration and braking, and the low speed of operation imposed by traffic congestion, noise reduction and safety requirements deprive urban passenger rail systems of nearly all of rail systems’ basic efficiencies.
The optimal speed and operation parameters projected in planning and design studies and documents tend to be unrealized under actual operating conditions, resulting in marginal or substandard performance, and inefficient overall service. Attempts to artificially increase daily ridership on rail services that fall short of projections and capacities have led transportation authorities to curtail bus and other transportation services that duplicate or compete with newly opened rail services, or to redirect or funnel riders toward new facilities. While such closures and redirection of services may concentrate ridership by limiting alternatives, the services that are curtailed or altered may be rendered less efficient, and their customers less well served.
Localized people mover operations such as that in airports, downtown business districts, and large assemblies of related activities such as hospitals or universities, often employ a tram or trolley mass transit system. Such systems often share roadways and pedestrian areas with other surface traffic. This combination and intermingling of incompatible activities tend to delay both the at-grade rail system and other surface traffic, while imposing significant safety concerns along the route of the rail system. The inherent risks of combining massive rail vehicle operations with much smaller automobiles and pedestrians are well documented. These risks can be minimized and mitigated, but to date no technological safety devices have been adequate to completely eliminate them.
Urban at grade rail systems often share the roadways and street surfaces with vehicles, and involve numerous at grade crossings of other streets, highways and pedestrian paths. The history of accidents, traffic congestion and safety hazards consistently created by at grade rail crossings adds to, and exacerbates the inefficiency of rail systems that operate in the environments of other transportation systems and activity settings.
Rural and inter-city at grade rail systems such as Amtrak include similar risks, albeit less frequent, but are subject to additional delays and collision risks because the tracks are often shared with freight train operations. Although the intensity and frequency of at grade crossings may be reduced, each such crossing is significant, and potentially hazardous. Often the crossings of local roads and unpaved agricultural access roads cannot justify the installation of automatic crossing gates, bells or flashing lights. In some cases, only a simple sign warns the driver crossing the rails of the possibility of a train’s passing. Train operating speed must often strike a balance, or compromise between efficiency of the rail system and safety.