1/3
bunda bir sorun yok bence. Metro gibi raylı sistemler ekspres güzergah gibi işlediği için ara yerleri pas geçer. Otobüsler bu ara yerleri de metroya veya ana artere bağlayarak doldur -boşalt yapar. Bu attığım yazının aynı kısmında da buna değiniliyordu:metro ile aynı güzergah giden bir kişi, metro yerine otobüs tercih ediyor, buda süreci mantıksız hale getiriyor
- * Georgist Economist February 28, 2018 at 12:14 pm #
While your concern is valid, it’s not a problem in practice for several reasons.
First off, there are several articles on this site about stop spacing and other issues of transit speed. Most notably, this article: http://humantransit.org/2013/03/abundant-access-a-map-of-the-key-transit-choices.html (istenirse atarım)
Thus in the maximum ridership example, you can safely assume that both lines are going to be something of a BRT, with their own lane (and signal priority, etc.) and 4-500 m stop spacing (as is entirely usual in Europe). As such, protected from congestion, it could easily have an average speed close of 30 km/h (20 mph) or so, doing no worse than cars (indeed, beating them during rush hour). (Note: *average* speed. Due to traffic lights and various other causes, cars with a top speed of 50 km/h get somewhere around 30 km/h average for the whole route. Distance traveled over elapsed time.)
In fact, there is a multitude of “fancy” solutions beyond BRT. If crosstown trips are still too slow — perhaps because transit must compete with an urban free-flow motorway — and sufficient budget is available, a single route can be split into an express/local overlaid pair. The express would have stops perhaps 1 km apart, while the frequent local would gather and scatter passengers from its colinear stops to the stops of the express. (There are minor problems with this arrangement, such as the fact that the express has far higher ridership than the local, and consequently — if using buses — a much higher frequency, which is wasted to some degree.) However, it is quite common for the express to be implemented with some form of rail vehicle, e.g. a metro. In this case, a frequent grade-separated (i.e. completely protected from congestion) vehicle with 1 mile (or longer) stop spacing afforded by the colinear collector-distributor bus can easily beat the car for the majority of trips. Look at London or Moscow for great examples of bus+metro systems.
Obviously, the above only apply if the city is large enough to warrant such a “fancy” solution. Most don’t, and simply a 4-500 m (quarter mile) stop spacing frequent bus with a car-free lane does the job just fine.
- Mike February 28, 2018 at 12:46 pm #
asdf2: I’m not sure about your assumptions. A straight crosstown coverage route doesn’t sound like a typical coverage route, or even a coverage route at all. The coverage routes are in your second example: long milk runs to downtown, sometimes five blocks parallel to a similar route or to a frequent route. Those are the bad coverage routes. The good coverage routes go to the nearest transit/shopping center from an area that’s considered too far from other routes and too essential to leave out of the network. These routes often turn and run on non-arterials because that’s the only way to reach their target endpoint and serve people in between. (TM3 ve TM2 bence buna güzel bir örnek) Some coverage routes may have two anchors (a good transfer/destination point at both ends), (TM15 bence) but that’s more due to a lucky happenstance that both anchors are available, or it’s an interlining of two theoretical routes (e.g., an L-shaped route) for efficiency or usefulness.
- asdf2 February 28, 2018 at 7:37 pm #
So, there are a lot of cities out there where the fastest road between two major activity centers is “fastest” because there’s not a lot of stuff along the way – so less stoplights and traffic to deal with. When you drive between the two points, this is the road you take.
But buses, as a rule tend to avoid such roads for reasons illustrated in this post – the more activity centers the bus passes by, the more trip pairs it serves, hence the more riders it can serve. This is all great from an agency productivity standpoint, but from a passenger experience standpoint, it means you’re taking a road with more stoplights and congestion to begin with, plus slightly longer distance, all so that the bus can stop at more bus stops (rather than blowing past them because nobody needs to get on or off), rendering the trip even slower. (Esenyurt otobüsleri)
Of course, in the ideal world, the “bus” along the two major roads would be an underground subway, completely immune to stoplights and traffic jams, and built to load and unload massive quantities of riders very quickly. When building a subway, you *have* to do “maximum ridership network”, or it’s too much money in construction cost chasing too few riders.
Even with buses, it is theoretically possible to achieve similar effects by setting up dedicated bus lanes and transit signal pre-emption. But, in practice (at least in the U.S.), all the roads are going to be designed first and foremost for cars, and the only choice the transit agency has is to throw buses on those roads to sit in the same traffic and wait at the same red lights as the cars do, on top of all the passenger loading at the bus stops.
Again, in such a practical network, the only way to get decent speeds is establish at least a few key crosstown routes, even if the intermediate ridership is weak, so it’s purpose becomes quasi-coverage, quasi-express-between-high-ridership areas.