I've got my disc of road rash running on windows 7, it is missing some colors but most are their, but it runs really brilliant. Really easy to do.
Step1: Open RASHDEMO.EXE and put for example c:\roadrash\ or what ever drive you want.
Step 2: Copy the contents of the ROADRASH folder on the CD into the new roadrash folder from step 1.
Step 3: Copy these three DDL's from the setup folder on the roadrash disc into the new road rash folder from step 1.
AWEMAN32.DDL
RASHICON.DDL
RASHPROP.DDL
Step 4: Run RASHME.EXE from the new roadrash folder and it should work.
Hope you enjoy

Also create a Save folder before running the game in the new folder or anywhere.