Seattle has this system all over downtown. Buses have two poles that go up to wires above the street, to power electric motors. Sometimes, the poles demagnetize and fall off the wires, so the driver has to go behind the bus and clap them together, and guide them back up to the wires.
Do the hybrid ones have any clever way to re-connect?
All the busses I've seen have this system where the driver has to walk to the back and pull on some rubber bands to put the tentacles back on the wires. If this could be automated, then perhaps you could omit wires at big junctions where it's most messy, needs lots of points, etc. Building & maintaining wires with 90% coverage might cost half as much as 100% coverage, I would guess.
Trolley busses can overtake each other, either by having a passing loop built in to the overhead wires or by briefly dewiring and rewiring the bus. Modern trolley busses can travel short distances off-wire and some can even rewire themselves automatically.
The only reason MBTA has had so many problems with unintended dewiring is that they have done little to no maintenance on the overhead wires for the last half century. You can expect that the same will happen sooner or later to whatever charging infrastructure they build for battery electric busses. That is, assuming that they even that far and don't just pull a bait-and-switch as soon as the wires are down.
The trolleybuses that Seattle is in the process of ordering are capable of driving off-wire on battery power for quite a ways (enough to bypass a construction detour), and can also detach and reattach themselves without the operator directly manipulating the wires.
Wire attachment is a big problem even for bus line me that are fully overhead. Before the buses had batteries, a detachment often required shutting down the road and bringing out a big truck to reattach the bus.
Seattle used to run dual gas/electric (not really hybrids since no battery) in the downtown tunnel by having them attach going in and Unattach going out. Great when it worked, but it often didn’t, so they just use cleaner emission buses now instead.
There's the risk of grounding from the vehicle to earth by a disbarking passenger, as well as of ground currents within 100m or so of a high-voltage downed line.
Mitigating those conditions requires specific actions and measures. Ensuring compliance by all passengers aboard the bus is a challenge. The lesser risk might be having them remain aboard. Even the option of carrying or assisting passengers from the bus could risk grounding. Consider that passengers might be old, young, handicapped, non-English speakers, or otherwise have difficulty understanding or complying with instructions.
I live in a city that transitioned from diesel buses to battery buses. I've never driven in a bus with trolley wires, but am very happy with the current situation.
First of all some of the roads in our cities are being replaced. No problem for the buses, take a slight detour and inform the public that one of the bus station is not in service for the time being. Such a replacement and/or maintenance would require much more planning with trolley buses.
Second, a big event was held in a weekend a couple of weeks ago, in a location not normally serviced by the buses. The roads near the event were closed off to all cars due to expected crowds, and visitors could get there on foot, by bike or by public transit (train or bus). Again, the buses extended their route to the entrance of the event, which would have been impossible with trolley buses.
I also imagine that the a trolley wires are vulnerable to vandalism and damage due to storms.
Yes, where the hybrid buses connect to the wires (usually at certain bus stops), the wires have sort of "tentacle catchers" on them, shaped as upside-down Vs.
The driver just has to stop on the usual spot, press a button, and while passengers are boarding and exiting, the "tentacles" unfurl, and are guided by these "catchers" towards wires. The driver just watches for a light to go on on his dashboard.
It works pretty well - in many years, I have only seen once that the tentacles did not end up where they should, and the driver had to get out and manually correct it.
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