Quote:
Originally Posted by ardecila
No, if you turned back certain trains at Chinatown you could run trains more frequently on the North Side without an overall increase in the number of trains.
However, if the Red Line ever upgrades to 10-car trains then CTA would need to lengthen yard tracks at Howard. The 95th Yard already has longer holding tracks.
|
It's already running maximum number of cars between Howard and South. The CTA is already running some rush hour Red Line trains on the Green Line tracks south of Roosevelt. If they go to 10-car trains, which they will need to do if the RPM project and increased development along the Red Line north continue the ridership growth at even close to the projections.
Their current maximum trains per hour on the Red Line is 30, but I don't think they actually run a full 30 trains per hour, I think 24 is their maximum, but they have multiple hours with 10-15 trains. If they have 4 hours of trains every 5 minutes, on average. A trip from Howard to 9th takes almost exactly an hour, so in a 4-hour period any given rail car can provide 2 full round-trips. So if there are 12 runs per hour of 8-car trains then you need enough cars for two hours in each direction for at least an hour to get the system primed. 8*8*2=128 cars, minimum, to support that service. The CTA's RPM documents project a need possibly as high as 35 Red Line trains per hour in 2040. That seems optimistic to me, but if that level of demand were to come to be, it could be met with either 35 8-car trains or 28 10-car trains. The same graph shows a maximum of about 22 Red Line runs per hour currently (in 2020). 22*8=176 cars per hour, and because each full run takes 2 hours to support that level for at least 2 hours requires double that, or 352 cars. I don't know what the CTA's in-service levels are, but lets say they can manage 90% in-service rates at the Red Line yards. That means they need to be able to hold 392 cars across the Red Line yards to meet the current maximum levels of service.
If their 2040 levels of service really do require the equivalent of 35 runs of 8-car trains, then they would require room for 623 cars, an increase of 59%.
And that's assuming that the projected 35-car runs assumes 8-car trains. If ridership actually demanded 35 runs per hour of 10-car trains, it would require 778 cars, or over double the current maximum needed. Now, chances are the CTA will not require that many cars, but either way the point remains the same that the CTA will need a lot more cars to meet projected demand.
Plus, turning back south of Cermak doesn't save as much as you seem to think. It takes 63 minutes to get from Howard to 95th, but it takes 45 minutes to get just past Cermak, basically a savings of 25% of the time and so if you turned back half of the runs, you're only saving about 12.5% of the needed cars. Even with that, you're looking at projected yard space increases of 50-60% more by 2040. You can't gain that by only extended track lengths at Howard, even if the space existed at Howard (which is a big if - maybe you could take over Triangle Park, but that would be unpopular and might not even solve the problem), because with additional cars, you need additional repair bays, too, and move for car movement for assembly and breakdown.
Prev
Linear Mode
