We had similar issues and had flashing lights and speed bumps installed on a campus crosswalk.  I don't think it makes sense to write a policy, especially for an off-site location that you can't control.  It's really about educating staff to have heightened awareness as the crosswalk and don't assume drivers are going to stop.

Deanna Prater BSN, RN
Director of Infection Control, Employee Health & Safety
Lower Umpqua Hospital
600 Ranch Road
Reedsport, Oregon 97467
Office:  (541) 271-6323
Fax:  (541) 271-6353
dprater@luhonline.com

“If you change the way you look at things, the things you look at change.”