One of Jane Jacobs’ prescient observations about bus service in The Death and Life is that one-way pairs, as practiced on the avenues in Manhattan, are bad for riders. Her argument was that one-way pairs require people to walk too long to the bus line, and this cancels out any gains in speed. (This is truer today, when signal priority is an option, than it was fifty years ago.) Jarrett Walker has formalized this in two posts using station radius as an argument; the issue is that passengers need to be within a short walking distance of both halves of the line, and this reduces coverage.
However, not all one-way pairs are created equal. An underrated reason to keep bus services on one line is simplicity: it’s easier to remember that a route follows one street than that it follows two, and also service to specific destinations can become easier. Taking a cue from proper rapid transit, ITDP’s magnum opus BRT standard treats it as a given that buses should run in the median of a street and only even lists one-way pairs as an option on very narrow streets, and even then as an inferior one. The argument revolves around service identity.
In particular, one-way pairs that preserve a semblance of service identity and simplicity are not as bad as one-way pairs that do not. For the original walk-distance reason, it’s also better to have the one-way pair closer together. Jarrett specifically praises Portland’s light rail one-way pair, located a short block apart, as an example of a good couplet. Manhattan’s one-way pairs are located a long block apart, so the walking distance is worse.
But even Manhattan’s one-way pairs are at least coherent. The First/Second Avenue bus follows First and Second Avenues for the entire length of the avenues; south of Houston, it follows Allen, the continuation of First. This is the advantage of the grid. In Providence, things are not as nice, though still somewhat coherent, if one remembers, for example, that Angell and Waterman Streets form a one-way pair (they’re treated as such for car travel, too, so anyone in the neighborhood would know, though people from outside would not).
In contrast, this is how Tel Aviv’s one-way pairs work. They’re getting worse amidst the various bus reform. The post is in Hebrew, but look at the map at the bottom of bus #5, the city’s busiest (and most frequently bombed back in the 1990s and early 2000s). The travesty is that none of those streets on which the line runs in one direction only is even one-way. East of Ibn Gabirol, the street hosting lines 25, 26, and 189 on the map, the streets are wide and two-way. The reason for the complication is lack of left turns. In order to make car traffic flow a little more smoothly, Tel Aviv has completely eviscerated its bus service.
In principle, Tel Aviv has infrastructure for consistent one-way pairs when necessary and regular two-way service elsewhere. For example, Dizengoff and Ben Yehuda, the two north-south streets hosting buses to the west, function as such for cars. They both have contraflow lanes for buses, allowing buses to use them as two-way streets; some do (for example, #5 on Dizengoff), while others still go one-way (for examples, #9 and #55). Likewise, Jabotinsky, the east-west street feeding into the big circuit, is one-way and narrow west of Ibn Gabirol, and could be a one-way pair with Arlozorov to its south; but Arlozorov is kept two-way, and so #66 is two-way, and #22 uses the two as a one-way pair. (By the way, those are fan-made maps; the official maps don’t use color to distinguish routes, and are thus completely unusable.)
The results of the mess coming from ending any service coherence are predictable. Israeli car ownership, low by first-world standards, is rising rapidly, and the social justice and affordable housing protesters are now complaining about high fuel prices. None of them is anti-transit on principle, and all who I confront tell me they’d ride transit if it were usable. I live without a car in a city with worse transit than Tel Aviv, but to me car ownership is not aspirational. When the only transit people know in their country is unusable, people this generation will get cars. The next bus reform will then take into account more left turn restrictions coming from the need to accommodate more vehicles. The next generation of people will grow up with the expectation of even worse bus service and not conceive of any alternative to automobility.