First off Google powered vehicles will only operate in zones. An unmapped road will never be apart of the mobility route. If they come across a road they do need currently deem suitable, then that road is simply not included in the mobility zone. Google have already demonstrated how they approach various conditions in which the roads are narrow. Such as pulling over or waiting behind a vehicle that is pulled over.

Google calls their Lidar, one that has a range of around 200 meters, a medium range Lidar. Which hints that they plan to develop one that has an even bigger range. In the scenario described, these type of roads are never very long. Like 100 meters or 200 meters. For us humans the solution is simple, one vehicle pulls into a space where there isn't a parked car to let the other vehicle pass. You never get a scenario where there are multiple cars in either direction and there are no spaces for cars to pull into. That never happens.

These vehicles know the road layout they are about the drive down in advance. They know how long the road is and how narrow it is. They can see and probably identify if there are any spaces upon entering such a road. They already have a significant advantage over humans.

Google have patents that demonstrate how the vehicle can also communicate with other drivers and pedestrians.

The most important thing to take into account is Google want to offer their tech as part of a community mobility package. Shared fleets. As I have already mentioned, such a road in the early days will not be included in the zoned area of deployment. But importantly, the kind of people who have parked their cars on such a road, they are the most likely people to drop car ownership for mobility on demand. After a short while that road with 200 cars parked on it almost permanently, becomes one with 100 cars parked on it. At which point a company like Google can then include such a road in their mobility zone, without making any alterations or advancements to their software.

In short, a shared fleet vehicle will not operate on any road it deems unsuitable (humans have deemed unsuitable). That includes weather conditions. It isn't a hard concept to grasp. What the other companies do, I frankly do not care. Google have shown exactly how roll out of this tech should begin. Mobility on demand in mapped zones in optimum conditions. What comes next is mobility on demand in mapped zones in almost all conditions. Then mobility on demand in all places in almost all conditions with the option for private ownership.