If it is a single carriageway, then the speed limit will be 60mph, unless it states otherwise or there are legal enforcements in place (e.g. roadworks/speed restrictions.)
You would have to state where your locale is. Speed limits vary by jurisdiction.
55
The humps do not affect the speed limit. The speed limit is determined by other rules and signs.
the same speed
There isn't one set, standardized speed for this. The construction site speed limit will vary according to a number of factors, such as number of lanes open, original speed limit on the road, proximity of work crews and equipment to the road, etc.The speed limit is whatever is posted on temporary speed limit signs.Rule of thumb is half the posted speed limit.
Depends on who administers the road. If it's a private road, the speed limit will be whatever the owner of the road determines it to be. In most instances of gravel roads not being private roads, they'll typically be county roads, and the county will have the jurisdiction to determine the speed limit.
Europe does not have a universal speed limit. It is dependent on the country, the jurisdiction, and the road itself.
The safest maximum speed for that road
isn't one.
Speed limits are based on the road, not the driver. Thus, unless another limit is specified, such as for trucks over a certain weight, the same speed limit applies to all drivers on that road.
Whatever the normal posted speed limit of the road is.
All vehicles get the speed limit on the road, whether it is a motorcycle motorbike or whatever, it it is a vehicle it has a speed limit.
Whatever the speed limit of the road you are driving on. There is no specific limit just for a railroad crossing.
NO NO NO