![]() ![]() Likewise for trains where the theoretical limit is 20K riders/hour, actual loading often tops out near 7K riders/hour. is 1200 riders per hour peak in Sacramento is about 1000 passengers/hr. Although LRT systems may be designed for high volume, the actual limit of any operating LRT system in the U.S. ![]() Now, compare that volume to LRT and trains. That would quadruple throughput to 7200 cabs/hour - roughly the volume of three freeway lanes in less than the space of one physical lane. After a few years of operation, we may have the confidence to reduce the headway times to only one half second. That approximates the maximum volume of a freeway lane of traffic (2200). That's 1800 people per hour assuming sole-ridership will prevail (30 cabs/min * 60 mins/hour = 1800 cabs per hour). At that headway, 1800 cabs per hour can roll down the guideway. Although automatic control of PRT cabs is safer and more reliable than human drivers, let's assume the Milpitas PRT system starts with that comfortable 2 seconds of space between each cab, aka "headway". PRT capactiy depends on headways:Ī commonly accepted safety margin on roadways is 2 seconds between cars. PRT vehicles every two seconds can provide the same capacity. For example, 60-passenger buses arriving two minutes apart (a very high flow rate for an American bus system) can carry 1800 passengers per hour. Uninterrupted flow is the key to capacity, not vehicle size. Mathematical Capacity, go to Passengers per hour: how to calculate transit capacity.Ĭan small cabs move large numbers of people like traditional mass transit? Yes. (86,400 p/d for each guideway X 50%) X 2 directions = 86,400 p/dĨ6,400 p/d compares well with the 55,000 p/d that VTA expects will use the BART Extension Phase 2 (BART Burrow) in the year 2040.įor a deeper examination of the Patronage vs. That yields 43,200 p/d per guideway, or 86,400 p/d for both directions. Let's apply a realistic throughput factor of 50%. Larsen to the TRANSPORTATION AND ENVIRONMENT COMMITTEE regarding the AUTOMATED TRANSIT NETWORK FEASIBILITY STUDY: Realistically, throughput for an ATN is likely to be much less – perhaps even less than half – of what would be indicated from an idealized capacity calculation derived from simple line-haul formulas. In the interest of accuracy, maximum possible throughput numbers should be reduced about 50% as noted in the Octomemo (page 5) from San Jose Director of Transportation Hans F. Even if each vehicle contained only 1 passenger, each PRT guideway could deliver 3600 people per hour (60 vehicles per hour X 60 minutes per hour) – or 86,400 (3600 p/h x 24 hr) passenger per day (p/d).ġ podcar with 1 passenger/second = 3600 passengers/hour = 86,400 p/d for each guideway direction ![]() Comparing PRT speed & capacity to other technologies.Īs with heavy freeway traffic, computer-controlled vehicles can be spaced 1 second apart.Estimating Passenger Throughput Capacity of PRT Technology.Professionals prefer those many small chainsaw teeth to the ax for removing wood chips. While ax heads are large with a big cutting edge, chainsaw cutting teeth are many, small and frequent. Perhaps the analogy of cutting a log with an ax vs. Many people jump to the conclusion that small vehicles cannot move as many people as large vehicles. As you can see in the following diagrams, PRT (Personal Rapid Transit), GRT (Group Rapid Transit), Light Rail, and Heavy Rail all travel at roughly the same speed (20 – 40 mph), but potentially transport widely differing numbers ranging from a few thousand to more than 50,000 passengers/hour.Ĭonfusion exists about PRT's capacity to move people. Capacity of a transportation corridor can be increased with larger vehicles, shorter headways, or both. Throughput capacity depends upon the number of people per vehicle and time between vehicles (headway). Throughput capacity of a transit system is how many people can be moved per hour or day.
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