I'm relatively new to the site, but I'm wondering why RI 51 is not included in the database. Like many RI state highways, the signage leaves a lot to be desired, but here's what I saw while driving in Cranston today:
I was driving on RI 12 westbound and saw immediately after the intersection with RI 5, the road was co-signed as RI 12 West and RI 51 West. A few blocks later, there is signage showing RI 51 continuing straight on Phenix Ave., while RI 12 turns right on Scituate Ave. I followed Phenix Ave. only as far as Natick Ave. to get to RI 37, and there were no additional signs for RI 51 through there. I highly doubt there are any other signs for RI 51 along Phenix Ave. all the way down to RI 115 in West Warwick. I know there aren't any signs for RI 51 from either direction of RI 115.