R5: US-50, West Sacramento, CA - update ramp names

This segment should be named Exit 3: West Sacramento / Jefferson Blvd[u] / South River Rd[/u] to match the last two exit signs.

This segment is not Jefferson Blvd, but rather to Jefferson Blvd.

This segment is to S River Rd.

Fixed

I think that the node for the split in that ramp should be move about 75 m sooner to reflect more closely the point at which traffic must be in the correct lane.

fixed