A sober sister program is a great idea, especially if you have sisters who might drive to bars or parties.
My chapter never had a formal SS program, but we didn't really need it:
- Most undergrads don't have cars
- Boston has good public transportation (as long as you're headed home before the T stops running at 1am

)
- The school runs Safe Ride, shuttle vans that take students to various spots on campus as well as to the off-campus GLO houses, free of charge. They run 7 days a week.
- At least 1/3 of my chapter didn't drink
So driving drunk wasn't really an issue. As far as getting trashed in general went, we looked out for each other, and if need be, we might "gently suggest" that a sister call it a night if she overindulged... but it wasn't anything formalized, just what sisters do for each other.