My approach would be to verify warrants for a signal, 2-way stop and 4-way stop (all in the MUTCD) One modification I would make it checking the warrants for the daylight hours, and the overnight separately. A lot of the signals in my area go to a flashing arrangement (yellow on major, red on...
Being as you are developing a database I think it would be more efficient to number the ramps. You would have 1 (or probably 2) fields for the street names(or better yet numbers from a roadway inventory or best an intersection ID number which can be traced back to a intersection description) and...