What is Light Rail Transit System (LRT)?
Light rail Transit is electrical power-driven passenger carts with steel wheels that are propelled along the track made with steel rails. The propulsion power is drawn from an overhead distribution wire by means of a pantograph.
The light rail transit and normal road vehicles share the urban streets, means vehicular traffic, pedestrians and LRT use the same space. Although Track systems are constructed within exclusive rights-of-way where vehicular traffic are prohibited.
Although in the shared street, it is recommended that the angle between tracks and motorbike path should not be less than 60 degrees. Otherwise, it will create a longitudinal slippery surface for bikes and in-case of braking, bikes may skid and lose control.
What are the Components of Light Rail Transit System?
Light Rail Transit Vehicle:
These are low-floor or partially low-floor vehicles with one or more independently rotating wheels instead of conventional solid axles.
LRV Bumpers are Front end of light rail vehicles are they designed around crash energy management (CEM) principles.
LRT Platforms are provided to the board and/or alight from the Trams. It is recommended that the LRT platform shall be constructed outside the curve sections of track to provide clear visibility to the Tram Drivers.
Longitudinal Gradient of the Platform should match the Track Gradient so the gap between the Platform and Tram remains consistent throughout the length of the Tram.
What is the difference between LRT and MRT?
LRT and MRT both are provided as a rapid transit system and carry commuters inbound and outbound between “Central Business Districts” or business parks and residential settlements.
Here are some key differences between LRT and MRT:
LRT is plied in a combination of segregated zone and shared zone with vehicular traffic. Shared zones are generally provided over the at-grade junctions and or high streets area within the city centres where space is a huge constraint, so the shared area caters LRT movements, vehicular traffic and pedestrians.
MRT are mostly plied in segregated space, away from vehicular traffic. MRT can also be segregated vertically by developing an elevated track.
Speed of LRT and MRT:
The LRT is operated at relatively lower speed compare to MRT. There are various reasons to have slow speed such as the frequency of tram stops, sharp bends along the tracks, multiple bends back to back due to space constraints, crossing the road junction at road level, etc.
However, MRT is generally operated at higher speed and segregated or elevated track compliment it. Also, the spacing between Stops are way higher in case of MRT than LRT, so MRT can easily accelerate the speed up to posted limits but LRT doesn’t receive that spacing between Stops.
Number of Carts:
MRT is operated with 6 to 8 carts and carries a larger number of commuters compared to LRT. LRT is operated with 2 to 4 carts and the length of LRT carts are also smaller than MRT carts.
What are the advantages and disadvantages of LRT against the Buses and/ or MRT?
Following are the key advantages and disadvantage of the Light Rail Transit System against Bur system or Mass Rapid Transit System.
LRT needs higher capital investment compared to the Bus System. So, it’s very important to examine the business case and Benefit-Cost Ratio (BCR) before proceeding the design of LRT System. Although the capital investment in case of MRT is way higher than LRT because of its long lengths, dedicated corridors, platform sizes and other factors.
The operation cost of LRT is quite competitive against the Bus System if it is compared with per-passenger operating cost. The operating cost of the MRT system is higher than LRT system.
LRT provides a better level of ride comfort compare to Bus system due to even levels of steel rails, however, the Buses are plying on the road and uneven road surface or potholes may create an unpleasant ride to the commuters. But comparing against the MRT, the ride comfort of both systems is nearly similar.
Last Mile connectivity:
LRT or MRT systems are designed to connect nodes of high trip generation or attraction points. As a result, they serve high demand locations efficiently but when it comes to last-mile connectivity, the catchment of Bus systems is far robust than LRT or MRT system.
Bus systems provide a high level of dispersion for commuters and therefore provide better last-mile connectivity.
LRT and MRT both systems are constructed are dedicated corridors and do not permit vehicular traffic of pedestrian to enter to that zone. Safety and protection measures are robust and protective for the worst-case scenario. As a result, the safety of LRT or MRT systems are way higher than Bus Systems.
But comparing LRT against MRT system, the safety system of MRT is higher than LRT system because LRT system sometimes interacts with road traffic and pedestrians at shared zone but MRT system never interfaces with road traffic or pedestrians.
Moderns Buses are generally operated by using CNG or Electric or similar energy system and generate very low-level carbon footprints. But MRT and LRT are operated by Propulsion power from an overhead distribution wire by means of a pantograph. So, LRT and MRT much eco-friendlier than Bus Systems.
Same applied to noise pollution. MRT and LRT systems generate fall less friction and noise than Bus Systems.
What are the Types of Tram Stops?
Following are the key types of Tram Stops commonly used, in case of Light Rail Transit Systems:
- Island Platform Stop
- Side Platform Stop
Island Platform Stop:
In the case of Island Platform, the platform stays in the middle and tram tracks are laid on each side of the platform.
Island Platform is suitable in an urban situation where land is a constraint and Side Platform is not feasible to accommodate.
Side Platform Stop:
In case of Side Platform, the inbound and outbound tracks stay at the centre and Platforms are provided are one side of the track for each track.
What is Pocket Track in LRT System?
Pocket tracks or withdrawing tracks are rail track arrangements, which permits trains to park off the main track alignment.
I hope this blog will help you understand the Light Rail Transit System and its associated features. Please feel free to like, share and comment.
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