The 1986 LRTA Study: Bus ai??i?? LRT ai??i?? Metro Comparison – Reprinted

I thought I would reprint this post from May 20, 2010 as it may clear up some major misconceptions about LRT capacity.

There is an ongoing debate today that LRTAi??can only carry a limited number of riders and that the magic number for a subway is about 100,000 riders a day on a transit line. This may have been true in the 1970′s, but not the 21st century, where modern multi-articulated low-floor light rail vehicles (tram is much easier to say!) are able to easily carry three or four times this number, thus negating the need for expensive subway construction, except on the most heavily used routes. If the LRTA found that modern LRT could carry over 20,000 pphpd in 1986, it is no stretch of the imagination that LRT can carry 30,000 to 40,000 pphpd if demands warrant, such as Karlsruhe Germany, where 45 second headways with coupled sets of trams are doing just that.


The 1986 LRTA Study: Bus ai??i?? LRT ai??i?? Metro Comparison

Posted by on Thursday, May 20, 2010 Ai??

A Vienna tram on a simple reserved rights-of-way.

The following is from the Light Rail Transit Associations hand book Light Rail Transit Today, comparing the operating parameters of bus, light rail, and metro on an unimpeded 8 kilometre route with stations every 450 metres. Using real data based on acceleration, deceleration, dwell time, etc., the study gives real time information for the three transit modes.

Please note: This study has been abridged for brevity and clarity.

The study assumes a vehicle capacity for a bus at 90 persons; LRT 240 persons (running in multiple unit doubles capacity); and metro at 1000 persons.

The time to over the 8 km. route would be:

  1. Bus ai??i?? 22.4 minutes
  2. LRT ai??i?? 18 .6 minutes
  3. Metro ai??i?? 16.3 minutes

The Round trip time, including a 5 minute layover:

  1. Bus ai??i?? 54.8 minutes
  2. LRT – 47.2 minutes
  3. Metro ai??i?? 42.6 minutes

The comparative frequency of service in relation to passenger flows would be:

At 2,000 persons per hour per direction:

  1. Bus ai??i?? 2.7 minute headways, with 22 trips.
  2. LRT – 7.5Ai?? minute headways, with 8 trips.
  3. LRT (2-car) ai??i?? 15 minute headways, with 4 trips.
  4. Metro ai??i?? 30 minute headways, with 2 trips.

At 6,000 pphpd:

  1. 1 Bus ai??i?? 0.9 minute headways, with 67 trips.
  2. LRT ai??i?? 2.4 minute headways, with 17 trips.
  3. LRT (2-car) ai??i?? 4.8 minutes, with 13 trips.
  4. Metro ai??i?? 10 minute headways with 6 trips.

At 10,000 pphpd:

  1. Bus ai??i?? 30 second headways, with 111 trips (traffic flows above 10,000 pphpd impractical).
  2. LRT ai??i?? 1.4 minute headways, with 42 trips.
  3. LRT (2 car) ai??i?? 2.8 minute headways, 21 trips
  4. Metro ai??i?? 6 minute headways, 10 trips.

At 20,000 pphpd:

  1. LRT ai??i?? 0.7 minute headways, with 83 trips.
  2. LRT (2 car) ai??i?? 1.4 minute headways, with 42 trips.
  3. Metro ai??i?? 3 minute headways, with 20 trips.

Comparative Staff Requirements on vehicles in relation to passenger flows. Station staff in brackets ().

At 2,000 pphpd:

  1. Bus ai??i?? 21 (0)
  2. LRT ai??i?? 7 (0)
  3. LRT (2 car) ai??i?? 4 (0)
  4. metro ai??i?? 2 (up to 38)

At 6,000 pphpd:

  1. Bus ai??i?? 61 (0)
  2. LRT ai??i?? 20 (0)
  3. LRT (2 car) ai??i?? 10 (0)
  4. Metro ai??i?? 5 (up to 38)

At 10,000 pphpd:

  1. Bus ai??i?? 110 (traffic flows above 10,000 pphpd impractical) (0).
  2. LRT ai??i?? 34 (0)
  3. LRT (2 car) ai??i?? 17 (0)
  4. Metro ai??i?? 8 (up to 38)

At 20,000 pphpd:

  1. LRT ai??i?? 69 (0)
  2. LRT (2 car) ai??i?? 34 (0)
  3. Metro ai??i?? 15 (up to 38)

Though the study is 24 years old and completed before the advent of low-floor trams (which decreased dwell times), it still give a good comparison of employee needs for each mode. Metroai??i??s, especially automatic metro systems do require a much larger maintenance staff than for bus or LRT and when one factors in the added high cost of subway or viaduct construction plus higher operational costs, Metro only become a viable proposition when traffic flows exceed 16,000 pphpd to 20,000 pphpd on a transit route.

Claims from other blogs that automatic metros can operate more frequent headways than LRT are untrue; automatic metros can not operate at higher frequencies than LRT, but if Metro is operated at close headways in times of low traffic flows, they do so with a penalty in higher maintenance costs and operational costs.

Taking into account the almost universal use of low-floor trams, operating in reserved rights-of-ways, combined with advances in safe signal priority at intersections; given an identical transit route with equal stations or stops, LRT operating on the surface (on-street) would be just as fast as a metro operating either elevated or in a subway at a fraction of the overall cost grade separated RoWai??i??s. Also, automatic (driverless) metros, though not having drivers have attendants and station staff, which negate any claim that automatic metros use less staff than light rail.

The LRTA study does give good evidence why LRT has made light-metros such a as SkyTrain and VAL obsolete.


5 Responses to “The 1986 LRTA Study: Bus ai??i?? LRT ai??i?? Metro Comparison – Reprinted”
  1. rico says:

    We agree….sort of….the key is ‘unimpeded route’ there is no reason why LRT should be particularily limiting on unimpeded routes….of course the more conflicts on the route the greater the loss of speed and capacity…or the greater the cost to maintain an unimpeded route. A system like the Ctrain in highway medians can have a large capacity without the need for major grade seperation, King George would have more turning conflicts but still be fine assuming a separate right of way. A corridor like Broadway that goes perpendicular to the main trafic flow, has short blocks, high flows of traffic,lots of pedestrians and lots of turn conflicts would require so much grade seperation to maintain speed/capacity it may as well be fully grade seperated and integrated with the existing system.

  2. zweisystem says:

    Who is going to pay for grade separation? It is all very nice to want grade separated transit, but how is it going to get paid for? In short it isn’t.

  3. rico says:

    If a route is too obstructed for effecient LRT at grade what is the better investment, a constrained LRT, grade seperation or status quo. My feeling is each situation will have its own anwser but that in a constrained route spending lots of money for little mobility gains is likely a none starter. The more expensive option of grade seperation may come out ahead in terms of cost per rider or cost per new rider, pretty sure it would on Broadway.

  4. zweisystem says:

    I doubt it, grade separation may lead to faster commercial speed, but certainly would not attract much new ridership. The transit customer wants his/hers transit on the pavement, ready to use and light rail bits the bill to a tee. The huge cost difference between grade separated transit and at-grade transit, becomes a millstone around the taxpayers neck, just like what is happening in Metro Vancouver today.

  5. Martin says:

    I have a better idea; Lets canecl this entire B.S. LRT crap altogether, it is the biggest waste of money I have ever seen in my life. Take a look at St. Clair an absolute disaster! You’ll save 5 min on existing surface bus routes and walk a lot more!Lets instead build an Eglington subway from Keele to Laird. Extend the Sheppard subway from Yonge to Downsview. Extend Yonge line to Steeles.They are going to extend the Spadina line anyway to York U. Put 6 lanes on Eglington W. from Keele to 401 and make extra lane diamond for express bus rush hour service, same from Laird to Kennedy on the east route. Yes use Weston rail route for streetcar LRT from Bloor up to Finch Hydro ROW. and use Finch Hydro right of way for north crosstown LRT way from Airport to Zoo. Then you can connect the Scarbrough line from Town centre to this. They can make 6 lane Sheppard from Don Mills with diamond HOV to this line as well. Don Mills rd already has HOV lane! Money spent = about the same, traffic surface disruption = much less. Future capacity = much greater as subways beat out glorified streetcar lines any day and these stupid LRT lines will disrupt surface traffic with this plan permanently causing traffic jams and much more CO2 output as well as lost time!Steve: The St. Clair car is only barely LRT by virtue of the fact that it has a reserved lane, but it is by no means an ideal implementation. Far too many concessions were made to motorists in the number of crossings and left turn signal arrangements, let alone parking and sidewalk width problems. The transit priority signals on St. Clair do as much to hold up streetcar service as to assist it, and buses running beside the streetcars can make better time in mixed traffic which gets better treatment. As for your subway dreams, don’t hold your breath. We can barely pay for what’s on the drawing boards now, and quite bluntly, the VCC extension is a travesty of politics over good planning. This should have been the beginning of an LRT network in York Region, but instead at vast expense we are building a subway whose projected demand is barely in the low end of LRT territory.

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