9 ms·
"New York has actually built an elevated train that travels above car traffic (and can't collide with it)" Is this really better than a standard elevated railw
by chris_7 10y ago
"New York has actually built an elevated train that travels above car traffic (and can't collide with it)"
Is this really better than a standard elevated railway? Trains fit much more than 300 people, already, today.
- flukus 10y agoIt's different. The use case for this is the same as light rail, shorter distances with more frequent stops. Basically this is to commuter rail as commuter rail is to high speed rail.
- geezerjay 10y ago> Basically this is to commuter rail as commuter rail is to high speed rail. In other words, this is a beefier trolley car. Same concept, larger capacity.
- flukus 10y agoYes, but one that doesn't have the costs of being elevated or the downside of being blocked by traffic.
- vonmoltke 10y agoHow is it not blocked by traffic? There is no way for something to use the same right-of-way as traffic and not be affected by it.
- superuser2 10y agoRTFA. It's a tall "bus" which straddles the roadway so that cars can drive underneath it. It does have to stop at intersections, but can also go faster than traffic on the same road.
- vonmoltke 10y agoI did. If it has to stop at intersections, how is it not subject to being blocked by traffic? If it is rolling along the same road, what stops cars from moving in front of it? As far as I can tell, this system has no advantages over a tram/streetcar.
- flukus 10y agoA tram can be blocked by traffic, not just lights but cars backed up at those lights. If there is a traffic jam then the tram has to sit behind cars, this things can just cruise over the top.
- vonmoltke 10y agoHow does it cruise over the top when all available ground space is covered in cars? The only way it can do that is to give it dedicated ground space, at which point what is the advantage over dedicated tram/streetcar lanes?
- superuser2 10y agoIt's very rarely the case that "all" available ground space is covered in cars; most roads have a bit of extra width, even if not enough for an additional car + separation with the next lane over. Gutters, shoulders, bike lanes, etc. Sidewalks are also often wider than they need to be - there's usually a dead two feet or so on the sidewalks of major roads where signs or parking meters are planted.
- vonmoltke 10y agoThat extra space has a purpose and will still be needed with this thing installed. Gutters are not just there for drainage; they also serve as a space buffer between sidewalks and the road in places that don't have swales for separation. Shoulders are there for parking and getting broken-down vehicles out of travel lanes. Bike lanes are for, well, bikes. You lose those functions if you want to install this and not replace the thing you removed. As for the ground area it needs, it appears that the rails are roughly the width of a suburban sidewalk[1]. Add guard rails to keep people and vehicles from interfering with it and you have close to half a travel lane on each side consumed by this. What then is the advantage to this versus taking a travel-lane's width for a tram or installing an elevated people mover? [1] http://www.borntoengineer.com/china-unveils-prototype-straddling-bus/#howitworks http://www.borntoengineer.com/china-unveils-prototype-stradd...
- geezerjay 10y ago> Yes, but one that doesn't have the costs of being elevated or the downside of being blocked by traffic. This is a false assumption. The elevated bus does block traffic when crossing intersections, which it does somewhat slowly due to restrictions on the turning radius, and it does block traffic from switching lanes. This doesn't mean the concept is silly. The main feature is that this concept doesn't require a dedicated tram path, nor does it appear to require extensive road work (i.e., installing a rail track).
- superuser2 10y agoCommuter rail is something like Chicago's Metra, with Amtrak-like trains and stops far enough apart that walking is out of the question. Elevated trains and subways in Chicago and New York can and do act as light (not commuter) rail with stops every few blocks.