Comment 121206

By Haveacow (registered) | Posted April 11, 2017 at 09:12:09

DETERMINING VEHICLE CAPACITY IS ONE OF THE MOST HARDEST (CONTRIVERSIAL) THINGS PLANNERS AND ENGINEERS WORKING FOR TRANSIT COMPANIES HAVE TO GO THROUGH. HERE'S WHY!

Using the TTC's capacity numbers is ok BUT BE AWARE, they have a tendency to under count when it comes to standing space. Generally the TTC uses a metric of capacity in a vehicle measured by the number of seats plus the maximum number of standee passengers. This is done by using the passenger per square metre metric, which the TTC uses as a maximum of 4 people per square metre x the availability of actual, standing space in square metres.

Using 4 passengers/sq. metre is okay but most times, TTC buses during peak hours are packing 4.2 to 4.3 passengers/sq. metre of space for standing passengers. In most cases when measured scientifically in studies usually by the CUTA and the APTA, 4.3 people/sq. metre is the point most North Americans start to really complain and when transit properties really start to loose choice passengers. These metrics also apply as well to station passenger platforms for rapid transit services. In North America half (50%) of the population will easily panic at any number above 5.15 passengers/square metre of standing passengers. This level is sometimes reached on the TTC's Yonge Subway Line between Bloor and King Street stations during peak times.

When you see, usually in the fine detail for transit vehicle brochures for bus or rail vehicle designs especially train builders, using counts of 6-8 passengers/square metre. This number is usually used to help calculate weight tolerances for vehicles not passenger capacity performance.

When it comes down to Light Rail Vehicle builders, they tend to be more accurate when it comes to this market (far fewer outrageous numbers) because they sell so many of these designs world wide. The 3 largest selling LRV designs world wide, Bombardier's Flexity LRV Family of products (3000+ plus built and on order), Alstom Citadis LRV Family (1700+ built and on order) and Siemens Combino/Avenio & S70/200 Family of products (2500+ built and on order, 1500+ in North America alone), have so many example vehicles available as examples, any claims made by these builders that are false or overblown can quickly be checked and confirmed because due to the fact that, there so many different transit properties each company has sold to. If there is a real problem with the design or the vehicle itself (beyond manufacturing and teething issues), it becomes quite obvious very soon.

However, all the biggest rail vehicle producers for the North American market Bombardier, Alstom, Siemens, Kiniki Sharyo, Stadler, CAF, and Breda have used this as a capacity determination measure for some rail vehicle designs at times, to bump up the numbers on certain products to make it look good and induce sales. Bombardier has been notorious for using this metric on their brochures and promotional material for their Innovia 300 Automated Light Metro Transportation System (Vancouver's Skytrain and the Scarborough RT). Bombardier has been using this metric to artificially bump up its actually very, very low capacity numbers on this product when compared to other Subway/Metro/Heavy Rail products both available from Bombardier and other rail vehicle producers.

On top of all this, regardless of how many people an individual rail vehicle can carry, electrical capacity can put a limit on everything. Debating Vancouver's Skytrain actual capacity in terms of passengers is further complicated because, the actual line can only handle so many trains per hour because of severe limitations of the electrical delivery system. Currently Vancouver's Expo Line runs at a limit of one train every 109 seconds as determined by their operating certificate issued by transport Canada. There is much debate locally that the automation operating system could handle one train every 75-90 seconds! Unfortunately, the electrical system which powers the trains can't. Upgrading this system to even add 5-10% more capacity will cost hundreds of millions of dollars. So each "Skytrain" line of the Vancouver system (not the Canada Line which has an even lower capacity) is limited to a frequency of service of one train every 109 seconds or a peak hour passenger capacity of about 14,500-15,000 passengers/hour/direction.

Complicating things is the actual amount of standing space on a vehicle. This can vary greatly depending on the seating configuration used. One other point is that, vehicle producers which used to be stalwarts on accuracy regarding these numbers lately, have stretched these claims to sometimes unbelievable proportions. They can stretch and exaggerate these numbers as well as the best used car salespeople anywhere. The TTC is actually very conservative when it comes standing space and IMHO tends to underestimate it by 10-20%.

Even when engineers and planners try to fix things its never perfect. In an attempt to simplify things, planners and engineers have switched to use a number between 4-5 passengers per metre length of vehicle, times the length of the vehicle (don't include the length of the operators cab) to help calculate standing room numbers. Unfortunately, this also can greatly distort standing space both positively and negatively because of seating configuration and especially, wheelchair space. Is it part of the seat count or part of the standing space count? Do you count it at all if its part of the standing space number? The jury is still out on this one. I bet you guys never believed just calculating vehicle capacity was this complicated!

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