Quote:
Originally Posted by JAM
if you can keep the road flowing at 60 mph on a 4 lane hwy with even 1 person per car - I'll let you do the math, I don't need to. This is far more humans passing a certain point that any train can handle.
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This is for anyone reading with an open mind, as I seriously doubt you do.
Okay, I'll do the math, since you seem incapable of doing so.
at a safe 3 second following distance, that's 1200 vehicles per hour per lane. So 4800 people per hour for 4 lanes.
So let's look at light rail, at ~200 passengers per car, with a 3 car set, each train is 600 passengers. So to equal the capacity of those 4 lanes, you only need a train every 7.5 minutes (not very high frequency).
But humans are shitty drivers, and frequently don't follow safely. Say a bunch of them are only following 1.5 seconds, so that the 4 lanes is up to 9600 passengers /hour (until those bad drivers cause an accident). Note that this is one reason why introduction of autonomous vehicles may actually reduce highway capacity .
The light rail can equal that by doubling it's frequency. *
Of course, the light rail can be depositing those 18k passengers /hour (coming from both directions) at a single spot downtown, while all those people on the highway are driving by downtown at 60 mph, with no hope of more than a small fraction of them being able to slow down and exit to downtown.
*The capacity of a heavy rail metro system, with say 8 car sets coming at 2 minute frequencies is left as an exercise for the reader.