Oracle Database Discussions

Hello I have a table with one sequence id (RT_ID) as Primary key and have several other column such as route_type, route_number, route_signing,road_number,county_id_fk,muni_id_fk,effective date and some more. I would like to create three unique key as follows
1) route_number,route_signing,effective_date
2) road_number,county_id_fk,route_signing,effective_date
3) road_number,muni_id_fk,route_signing,effective_date

But it does not work . I can create first record with no problem , but when trying to create a unique record for second unique key it gives me error for third unique key.

Is there a problem in this design because some of the columns are shared in all kind of unique key.? Do I have to create three seperate tables for every unique key ?

thanks

Suhail