Light Rail Speed and Stop Frequency

Light Rail Speed and Stop Frequency

In some areas, "light rail" may also refer to any rail line with frequent low speeds or many stops in a short distance. This inherits the old definition of light railway in the UK. Hong Kong's Light Rail is an example of this, although it is also called "light rail" because it is a lower-scale system than the rest of the MTR.

Sprinter in the San Diego area uses DMUs and is targeted towards a commuter rail audience, however, because of the large number of stops along the line, it is called the light rail.

Reference speed from major light rail systems, including station stop time, is shown below.

However, low top speed is not always a differentiating characteristic between light rail and other systems. For example, the Siemens S70 LRVs used in the Houston METRORail and other North American LRT systems have a top speed of 55–71.5 miles per hour (88.51–115.1 km/h) depending on the system, while the trains on the all-underground Montreal Metro can only reach a top speed of 72 kilometres per hour (44.74 mph). Los Angeles Metro light rail vehicles have higher top and average speeds than Montreal Metro or New York City Subway trains.

The main difference is that Montreal Metro and New York City Subway trains carry far more passengers than any North American LRT system, and the trains have faster acceleration, making station-to-station times relatively short in their densely populated urban areas. Most light rail systems serve less densely populated cities and suburbs where passenger traffic is not high, but low cost combined with high top speed may be important to compete with automobiles.

Light Rail System-Wide Considerations

Many light rail systems (even fairly old ones) have a combination of both on- and off-road sections. In some countries (especially in Europe), only the latter is described as light rail. In those places, trams running on mixed rights-of-way are not regarded as a light rail but considered distinctly as streetcars or trams.

However, the requirement for saying that a rail line is "separated" can be quite low—sometimes just with concrete "buttons" to discourage automobile drivers from getting onto the tracks. Some systems such as Seattle's Link had on-road mixed sections but were closed to regular road traffic, with light rail vehicles and traditional buses both operating along a common right-of-way (however, Link converted to full separation in 2019).

Some systems, such as the AirTrain JFK in New York City, the DLR in London, and Kelana Jaya Line in Kuala Lumpur, have dispensed with the need for an operator. The Vancouver SkyTrain was an early adopter of driverless vehicles, while the Toronto Scarborough rapid transit operates the same trains as Vancouver, but uses drivers. In most discussions and comparisons, these specialized systems are generally not considered light rail but as light metro systems.