I’ve said that I think there would be downsides to running surface-level light rail along the Broadway corridor.  I don’t think they’re overwhelming, and I don’t think they decide the issue.  But I think it’s at least worth clearly taking stock of them.  So I want to start to do that, although I’m only going to focus on one set of related issues now, and not try to catalogue them all.

Broadway is a six-lane street.  There are a few different ways you could configure lanes of traffic to make sure trains weren’t getting stuck behind drivers turning right or left.  For example, you could have a lane in the middle of the road for lefthand turns and boarding platforms for the trains.  Then the lefthand lanes would be for the trains, the righthand lanes for cars, and parking (or a bike lane?) would be on one side of the street.  Or whatever.  My point is that, so long as the trains have their own lanes — so they’re not getting stuck behind drivers turning — there’s only one lane of car traffic in either direction.

Now, I’m not one to care about space on the roads for cars.  But with only one lane of traffic in either direction, there doesn’t seem to be any space for local buses* — and that, I think, is a problem.

But, you might think, why would Broadway need buses if it has a rail line?  If the rail line’s going to be rapid transit, it needs to be a limited stop service.  Stopping more often than the 99 stops now is going to slow the train down.  Okay, so maybe it doesn’t have to slow the train down too much.  After all, unlike the 99, we’re supposing this train’s never going to get stuck behind cars turning, and we’re supposing it’s going to have a solid signal priority system, so it doesn’t get stuck at red lights too often.  So maybe we can put some extra stops in to make up for the loss of the local service.  What would that look like?

Well, if we had as many stops as the local service does now, that’d be roughly every two blocks, or about every 350 meters.  (The blocks on the route vary in length, so that’s a rough average.)  But right now the B-Line makes 11 stops (including the end of the line) along a 13 kilometer route.  That’s a stop about every 1.2 kilometers.  (Again, that’s an average.  Some stops are a little closer together, and some a little farther apart.)  So talking in really rough figures here, you could double the number of stops on the route, and you’d still be making seniors walk a block farther to catch the train than they walked to catch the bus.

So there’s a really ugly trade-off here.  If the train ran a local service, it’d dramtically slower than the B-Line.  In no sense could it be considered rapid transit.  But if the train were even as fast as the B-Line, it wouldn’t be running a local service and would be dramtically less accessible to anyone with bad mobility.  Or we could try to strike a balance here, where it was only somewhat slower than the B-Line is now, and only somewhat less accessible than the local 9.

(* I’m not 100% sure of this.  I’d be interested if someone could describe a way to fit two lanes of trains onto a six-lane street and still have room for at least a lane in each direction of car traffic plus local buses — and have a way for both bus and train passangers to load and unload safely.  Of course, this problem goes away completely if Broadway were closed to car traffic.  A boy can dream. . . .)