This is an interesting idea though I'm certain that the active player amount will be low in this server. In combination with the huge SCS default map, it will be very, very empty.
And because the estimated player amount is low, this suggestion is likely going to get declined.
The main part of the community is interested in traffic, traffic jams and most aren't interested in obeying speed limits or other road laws.
Maybe one could combine this idea with a smaller, maybe 1:1 map, where people are more "cramped" into a smaller space so lower player amounts don't make the map feel so dead?