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Traffic Congestion

Chapter 1 Introduction

Traffic congestion becomes a major issue for development in many cities. To provide better mobility for city inhabitants, city governments in different counties invest public transit as alternate choice for intra-city transportation. In recent decades, Bus Rapid Transit (BRT) and Light Rail Transit (LRT) become famous choices for transit planners for mid-sized cities as improvements on their public transportation system to residents as alternate and increase the role of transit and decrease care dependency thus relief traffic, especially during commute hours. In most cases, both systems provide higher speed, capacity and better recognition system compare with conventional bus lines. Both BRT and LRT share many similar characteristics to each other. On the other hand, both systems have their own advantages and disadvantages over the other. This report will analyze and compare their benefits in different fields.

Chapter 2 Description of BRT and LRT

According to ITE Planning Handbook, BRT and LRT belongs to semi-rapid transit system that both transit modes have hybrid characteristics of street transit (e.g. conventional bus and trolleys) and Rapid Transit system (e.g. Heavy Rail, Commuter Rail). In many cities, both BRT and LRT work as a feeder or low cost alternative to Rapid Transit System. For example, Los Angeles Metro Orange Line (BRT) connects Metro Red Line (Red Line) at North Hollywood which continues to downtown; Metro Gold Line (LRT) connects Metro Red Line at Union Station from Pasadena and East Los Angeles, suburb of Los Angeles area. Miami Busway connects Metro Rail from downtown Miami at Dadeland South Station to the southern suburb of the city. In addition, the handbook defines three major types of right-of-way for BRT and LRT. They are:

Category A right of way is the system that exclusively separated and fully access-controlled right of way without intersections or access by other form of transportation.

Category B right of way has system that separated from other traffic with traffic controls and intersections, usually has signal priority and/or protected gates over other mode of the transportation.

Category C right of way is the system which share the mixed traffic, usually has signal priority at the traffic controls or intersection.

LRT system generally running in Category B right of way but can also use categories A and C. BRT system usually has Category C right of way but many "rail-like" type of BRT system (e.g. Los Angeles Orange Line) enjoys Category B right of way Reserved right of way usually on median of road or freeways. In US, BRT and LRT some time built on abandoned freight and trolley lines (e.g. Los Angeles, Minneapolis). Some BRT and LRT system in central area are running in underground tunnel (e.g. Boston and Seattle) to avoid traffic congestion in downtown area.

Both BRT and LRT vehicles usually are low-floor or custom designed for the specific line such as leveled platforms at stops or stations. BRT vehicle in US commonly are 60 feet long with capacities form 70-100 passenger per vehicle, in some cities they have doors on both side of the bus that can fit the both center and side station platforms. LRT are commonly are 100 feet long for one single car with option of multiple units running at the same time. Each light rail car has capacities range from 150-300 passengers. Typically, BRT and LRT vehicle can achieve speed of 65 mph on exclusive right of way.

Chapter 3 Research Literature Review

Statement: To collect articles with information, statistics and analysis regarding Bus Rapid Transit (BRT) and Light Rail Transit (LRT).

Los Angeles Metropolitan Transportation Authority. Rail Survey Report (2009) provides ridership, basic rider information and traveling patterns on current Metro Rail and Bus line, including Light Rail Transit, including Metro Gold Line (Light Rail) and Metro Orange Line (Bus Rapid Transit) as sample comparison in this report.; Los Angeles Metropolitan Transportation Authority. Bus vs. Rail Crime Comparison. (2009), suggests no significant impact on crime rely on the geographic over model of the transit.

Institute of Transportation Engineers. ITE Planning hand book, 3rd Edition. (2009). defines, classify and describe about Bus Rapid Transit and Light Rail Transit. It also provide a overview about both transit modes in terms of average trip lengths, revenue service average speeds, descriptions about different right-of-ways, transit cost structure, funding sources, and general system performances.

Shen, (2007) examined and measures the service performance of Light Rail and Bus Rapid Transit. The article provides sample on various system in US, Europe and Asia and evaluate capital and operation cost for light rail and BRT. The articles concludes Light Rail favors higher transit volumes and longer distance trips while BRT has higher flexibility on mixed traffic arterials.

Richard (2007) examined the influence of the rail program on bus transit in Los Angeles. It suggests that rail is faster then buses even with transfer, and it is also cost effective and its fair share of subsidies other then buses.

Stutsman (2002) compares benefit and weakness of Light Rail and Bus Rapid Transit. He concluded that Light Rail on the planning has advantage on headway, safety on grade crossing then Bus Rapid Transit.

Sorensen et al.) (2008) examined data to characterize traffic congestion in Los Angeles, it also examined land use features in Los Angeles to determine the key factor about congestions in the area. Finally it identifies some possible solutions, including Bus Rapid Transit and Light Rail Transit, to help to reduce traffic in L.A. area.

Pecheux, & Saporta (2009) describe different type of collision between Light Rail Vehicle (LRV) and vehicles at signalized intersections on arterial and suggests mitigation measures such as lower train speeds, red light camera, physical barriers, and standard crossings.

Patankar, et al. (2007) evaluates the impact on Bus Rapid Transit lanes over the mixed flow traffic and determines overall benefit to city mobility in India. After a study and modeling on different transportation model in the city, it conclude it has overall positive impact to mobility of the region.

Chapter 4 Comparison of BRT and LRT

Construction/Capital Cost

One of the major advantages of BRT system compare with LRT is the construction and capital cost. BRT system typical LRT type system (e.g. Los Angeles Metro Orange Line) which has exclusive right-of-way, stations with pre-paid ticket machine is about half of the capital cost of LRT. BRT system on HOV lane (e.g. Los Angeles El Monte Busway, Pittsburgh Busway) is about one-third construction cost of LRT. BRT system on mixed flow lane (e.g. Los Angeles Metro Rapid System, Las Vegas MAX System) is about one-ten construction cost of LRT system. The reasons of high construction and capital cost of LRT is new light rail system usually needs a new rail yard, track electrification and power stations. On the other hand, most BRT vehicles can share the current bus main service facilities for storage and maintenance. Furthermore, the cost of each light rail vehicle cost about 3-8 times compare with BRT vehicles. For example, Light Rail Vehicle using on Metro Gold Line in Los Angeles cost about 2.9 million US Dollars per vehicle, Buses use on Metro Orange Line cost about eighty-four hundred thousand US Dollars per vehicle.

Operation

New LRT system requires new recruitment and training for new train operators to practice new system. On the other hand, BRT only needs few training from current bus operator within transit authorities to practice the system. BRT also enjoys more branches of line (e.g. Boston MBTA Silver Lines) and enjoys higher flexibility on labor by transferring existing bus operator from existing conventional bus system to BRT system. BRT also enjoy advantage that vehicle and pass each other within the corridor which some system took it as advantage to provide “express” service (e.g. Miami Busway) which some bus provide faster service by skipping stops along the busway. BRT also enjoys operation on less training on personnel at the beginning; however, LRT has long term advantage of using fewer operators over BRT with same amount of capacity. It is because a typical LRT vehicle can carry up to 200 passengers per vehicle with option to run as pairs. On the other hand, typical single articulated BRT bus can carry up to 100 passengers. Los Angels Metro Gold Line, a LRT system use only one-third number of service equipment then Metro Orange Line, a BRT system which has about the same ridership, service mileage and number of stations. In addition, case study for Saint Louis Metrolink Light Rail shows that LRT system is 15% lower on operation and maintenance cost in terms of per passenger per mile compare with their own bus system. In general, LRT operates at higher speed then BRT which also led to use fewer vehicles then BRT within same distance. Moreover, Light Rail vehicle service life is around 30 years comparing with Buses which averaging from 12 to 15 years. Hence, LRT enjoys lower operating and maintenance cost thus the overall cost in long term compare with BRT.

Neither BRT nor LRT system has true benefit on operation speed. Although in general light rail vehicle has higher top speed then buses, the operation time on the corridor depends on right-of-way, number of stops, signal co-ordination and fare collection system being used on the system.

Safety Issues

Most of the safety issues for BRT and LRT are collision of vehicles and cars and pedestrians at the at-grade intersections, especially when transit vehicles operate at high speed and have a priority over the mixed traffic. Los Angeles Metro Blue Line (LRT) and Metro Orange Line (BRT) both face several severe collisions between service vehicles versus pedestrians and cars at intersections and crossings since operation. Both LRT and BRT system usually needs to have extensive mitigations and signs to ensure drivers to get familiar and ensure them follow the traffic regulations when passing through at grade separations.

Due to nature of BRT system with lower cost of capital and construction, almost all BRT system in the world are not running exclusively from general traffic and using at-grade crossings. On the other hand, many LRT system design usually consider grade separation at major intersections. Grade separation besides provides better right of way thus less interference of mixed traffic and better on-time performance, it can also a key benefit to reduce possible collisions between light rail vehicles and passenger cars.

Planning/Environmental Impact

LRT has impact on noise level between rail cars and tracks, train horns and crossing gate bells. Studies and report from Los Angeles Metro shows South Pasadena residents concerns about train horns, bells at the railroad crossing and train running through their residential neighborhoods after Metro Gold Line has been built. As the result, trains are running at low speed as well as some special design on railroad that warning voice level at the bell is lower then general railroad crossings. Studies also show BRT system also has concern about noise impact to neighborhood. In contrast, noise level for LRT system can be reduced by special design of tracks, on the other hand, even with mitigations; engine noise from BRT vehicle is significant unless running as trolley-bus or electric hybrid type system such as Boston Silver Line or Metro Tunnel in downtown Seattle.

As mention in Chapter one, both BRT and LRT used as feeder of Rapid Transit in some cities in the world that helps to reduce traffic, especially commute traffic during rush hours. For BRT, if the system designs as LRT type system (e.g. prepaid fare system, park-n-ride lots at the stations), it generally gives rider as rail like type system as well as ridership can be comparable with LRT system. Therefore, in terms of planning impact, both BRT and LRT has similar image to residents as new alternate of transportation.

Chapter 5 Conclusion

BRT has higher flexibly on capital cost and design, faster implementation times and simpler technology than LRT due to no tracks and line electrification needed. However, the capacity and the capital cost of BRT system is greatly affected by Right-of-way configuration. In long term LRT enjoys lower operation cost then BRT since BRT is more labor-intensive while LRT is more capital-intensive. However, the true advantage of each system can be offset by design, labor cost, existing right-of-way, and acceptance by local residences of each city. For instance, many current light rail lines in Southern California region were built on abandon former Pacific Electric Trolley and freight lines. In this case, LRT system enjoys lower capital cost due to existing right of way and rail maintenance yards. It is necessary that Transit Agencies to evaluate various criteria beside capital cost for a users and environmental friendly with best benefit transit system to the city.

Reference:

  1. Amanda Covarrubias, (et al) Crashes Heighten Busway Concerns Los Angeles Times, November 03, 2005
  2. Institute of Transportation Engineers. ITE Planning hand book, 3rd Edition. (2009). Page 679-710.
  3. Light Rail Now! Publication. “Free” buses vs. “expensive” rail? May 31st. 2007. http://www.lightrailnow.org/myths/m_mythlog001.htm
  4. Los Angeles Metropolitan Transportation Authority (2009). Ridership data report. Oct 2009.
  5. Los Angeles Metropolitan Transportation Authority (2009). Bus vs. Rail Crime Comparison. June 2009
  6. Los Angeles Metropolitan Transportation Authority (2005). Special Board Meeting Archive. September 22, 2005.
  7. Los Angeles Metropolitan Transportation Authority (2009). Board Meeting Archive. September 22, 2009
  8. Los Angeles Metropolitan Transportation Authority (2008) National Transit Database Report. Federal Transit Administration. June 2008.
  9. Patankar, V.M. et al. (2007) Impacts of Bus Rapid Transit on Traffic and Commuter Mobility. ASCE Journal of Urban Planning. P.99-106. June 2007.
  10. Pecheux, Kelley. & Saporta, Harry (2009). Light Rail Vehicle Collisions with Vehicles at Signalized Intersections. Transportation Research Board.
  11. Shen, David & Hsu, Rosa (2007). A Comparison of Light Rail and Bus Rapid Transit. Florida International University.
  12. Sorensen, Paul (et al.) (2008) Moving Los Angeles: short-term policy options for improving transportation. RAND Corporation. 2008.
  13. Stanger, Richard (2007). An Evaluation of Los Angeles Orange Line bus way. Journal of Public Transportation. Volume 10, no.1. page 103-119. Stutsman, J.M. (2002) Bus Rapid Transit or Light Rail Transit—How to Decide?: Los Angeles Case Study. Transportation Research Board. Issue number 1793. p55-61.
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