One of One-Sixty wrote:Look at NJT riverline from Camdem to Trenton, and they share same tracks with Conrail, NS and CSX.
Well, the River Line has an arrangement to make that possible: light rail and heavy rail don't operate on shared rails at the same time. On the southern part of the line, down by Pavonia Yard, the light rail has its own dedicated tracks, but further north it's light rail by day, freight by night. This time seperation is how they got FRA approval to run the LRVs on that line, without them needing to be crashworthy to the same standard as a "normal" train.
The process doesn't work when passenger trains are involved, because passengers start to complain if you leave them sitting in a yard for a few hours.
I don't know that mall traffic would be sufficient to keep the numbers up for any line (heavy or light). Firstly, after a day of shopping, it's a lot easier to throw several bags of stuff in the trunk of a car than to lug them onto a train. Second, where is the service starting from, and where is it stopping? The stops would have to be in places where there are already people nearby; you're not going to draw people to drive any distance to the station to take a train to the mall, when they could just drive right to the mall.
From my experience in NJ with the Hudson-Bergen light rail, LRVs aren't suited to big loads (most recently, I dealt with taking the light rail back home after the 4th of July fireworks). The capacity of a single LRV is already less than just one "normal" train car, and I've never seen more than two MU'd together operating in revenue service (on the HBLR or the River Line). With a large number of people from the mall, with several bags of stuff, it would get really crowded really quickly.
The same would be true of service to/from the Coliseum. One need only look at the situation with PATH trains in Manhattan after a concert at MSG. By the time the concert is over, you're almost certainly in an "off peak" time and so you have less scheduled service to begin with. If you kept scheduled 15-minute headways, you're going to have a lot of people waiting. A HBLR car has a seated capacity of 68 people; double that for standees, and maybe the MTA had the forethought to "double up", and you're taking about 270 people with each trip. You'd probably end up with the "Belmont effect", where trains fill up to capacity, and lots of people are left waiting for the next one. Unlike Belmont, though, there's not likely to be any extra service. The end result is a lot of people waiting for a train, and then trying to cram their way in. I don't know about most people, but I'd rather be sitting in my car waiting to get out than waiting in a long line for a train (where I know I'm inevitably going to end up being pushed around and sandwiched between several people).
I'm not sure that running regular rail service would be any better, though. You gain extra seats on each train, but you wouldn't have the same frequency of service .
I suppose it all depends on what the point of the service is. Are you trying to serve the mall, trying to serve the coliseum, or trying to serve office space? The "right choice" depends on what problem you're trying to solve.