Is there a calculation as to how many hours would be lost spent on the road because of a speed limit? Like I don't know, say every day people spend a million ho

Is there a calculation as to how many hours would be lost spent on the road because of a speed limit? Like I don't know, say every day people spend a million hours driving on the highway, and a speed limit would bump it to 1.2 million hours (no idea, just made up numbers)?