Capital Costs to Build Various Forms of Transit
Costs of transportation infrastructure can be divided into 2 parts - capital costs to build it, and cost to maintain it (operations and maintenance, O&M). Click here to examine capital costs. Click here to learn about PRT's very low cost of O&M.
Transportation Options Through a PRT Lens offers an introduction to various transit factors. Page 9 of that document presents the following cost estimates for various transportation technologies. All are compared using a corridor model with travel going both ways (bi-directional). While the specific costs and estimates will vary, each mode generally maintains its cost-position relative to the others.
|Transportation Technology||Bi-Directional Cost Range|
|Bus Rapid Transit (BRT) – when re-purposing existing roadway||$4-9M/mile|
|Freeway/Expressway Lanes – at ground level (no land acquisition)||$10-20M/mile|
|Personal Rapid Transit (PRT) – elevated||$20-60M/mile|
|Automated People Mover (APM) – at ground level||$30-50M/mile|
|Light Rail Transit (LRT) – at ground level||$60M/mile|
|Bay Area Rapid Transit (BART) – at ground level||$130-230M/mile|
|Pedestrian Over Crossing (POC) – elevated||$150M/mile|
PRT costs already compare favorably with APM, LRT and BART. After adding in land-acquisition costs to BRT and Freeway Lanes, PRT will likely be less expensive than those options also. Elevated versions of APM, LRT and BART would cost twice as much as ground-level corridors. Undergrounding often costs 3X the cost of at-grade versions. In the case of the BART Burrow (BART Extension Phase 2) the 2020 estimate is $1000M/mile ($6B for 6 miles), or 4X the at-grade cost of BART Extension Phase 1 ($2.3B for 10 miles). At $30M/mile for PRT technology, only 3% of BART's cost would be needed to provide similar service to downtown San Jose.
PRT increases ridership
When considering the financial cost of PRT infrastructure, one must also consider non-financial benefits such as the effect upon public transit ridership generally and the actual service provided to users. In other words, service levels of a transit system can be observed through both cooperative and competitive filters, i.e. synergy or increased ridership of the network of transit systems, and the actual advantages of PRT compared with other options.
Less Infrastructure Stuff = Less Cost
These images of the monorail at the 1967 World's Fair in Montreal show the relative size of the monorail along with the tight turning radii and flexible routing of such small-scaled system. Due to size of the vehicles (12 passengers rather than 4), the monorail is physically bigger than the LoopWorks' guideway, and it requires supports that are both larger and more frequent. (These screenshots come from an 8-minute film about the Fair.)
Comparing Transit Guideway/Track Sizes
This image shows the relative sizes of Disney Monorail guideway, elevated LRT railbed, and PRT guideway. The small print shows that the Disney Monorail uses 5,800 cu. yards of concrete and 1200 tons of steel per mile, while the elevated LRT railbed uses 28,000 cu. yards of concrete and 2900 tons of steel per mile. The elevated LRT railbed built through Milpitas cost about $120M/mile. As you can see, TriTrack (a minimalist type of PRT) uses far less concrete and steel, and therefore costs far less to build. The LoopWorks guideway will be about twice the size of TriTrack guideway.
This graph shows relative costs of 5 configurations of guideway. Type 2, supported, is the type used by LoopWorks and generally costs the least to build. As you can see, spans of about 30 meters (90 feet) are most cost-effective.