Most of Japan's expressways now are offering the weekend and holiday deal whereby one can drive for a flat rate of 1000 yen regardless of distance if one uses the ETC (Electric Toll Collection) system.
The idea is to increase tourism in the hinterlands and stimulate the economy, and it seems to have accomplished this to a limited degree. However, TANSTAAFL.
Predictably, this has caused traffic jams even worse than the usual ones...and the usual ones commonly run to tens of kilometers of barely moving vehicles for hours at a time during holiday peaks. There seems to have been some mitigation of traffic jams at toll gates since the system was introduced; it's said that about 30% of congestion occurs at toll gates, and that's reduced somewhat by the no-stop ETC toll collections. On the other hand, service areas and exits appear to have become more congested than before in many cases.
This should surprise nobody. It was predictable by anyone observing the very similar results of offering late night and early morning ETC discounts, introduced a while back apparently mainly to encourage truckers to drive at night and thus reduce overall congestion on the expressways. What it actually did, as far as I can determine, is push a lot of truckers, particularly long-distance ones, into waiting around on the normal roads until discount time, then onto the expressways. There seems to have been an increase in accidents due to sleepy/fatigued truckers, and congestion appears to have been moved around time-wise without any significant reduction overall.
In addition, the weekend and holiday all-you-can-drive-for-1000-yen ETC discount isn't quite as good a deal as it seems. There are some significant non-participant areas in the expressway system, notably the metropolitan expressways, where some token discounts are available but the 1000-yen cap doesn't apply.
This means that, for example, if I were to go from my office to my house in Kumagaya, I'd pay around 1000 for the combination of Tokyo Metropolitan Expressway (usually 700 yen) and Gaikan connecting ring road (usually 500 yen), then 1000 yen for the Kanetsu Expressway trip to one of the two exits near Kumagaya. At full fare this journey costs 3100 yen, so the saving isn't that significant.
Also, it's a one-time deal in its current implementation. Once you leave the expressway, the deal is done; you pay another 1000 yen when you enter again.
This is particularly significant for motorcyclists with passengers,who aren't allowed on some sections of the expressways, depending on local traffic safety administrations. They have to get off and travel on the normal roads until they reach a place where they can reenter the expressway...and then pay again. Since it costs around 12,000 to install the system on a car but about 20,000 on a bike, I won't be doing that anytime soon.
The current ruling party has talked about making expressways free, but frankly I don't think that's going to happen anytime soon. The responsible cabinet minister has announced that the current system will be changed soon , with wide-ranging caps on tolls, but I'll wait and see whether that actually happens next June as planned, and how it's finally implemented if/when it is.