Follow the nightly wait time on Saferide's Twitter site(https://twitter.com/NUSafeRide):
Its hard to know exactly how long in advance you need to call in order to book a ride with SafeRide. Demand for the service varies widely based on many outside factors from campus events to weather, such as rain, snow or if it is a weekend or not. When you call SafeRide to request a ride the dispatcher will provide an estimate of the time your car will arrive along with your wait time.
During the 2009-10 academic year the average wait time for a SafeRide vehicle was 35.30 minutes, with an average of 303.22 nightly passengers and 70,449 yearly passengers. The wait time increased to 43 minutes in the fall of 2011.
Wait times tend to be longer in general on weekends, and nightly between 10pm and Midnight.During adverse weather conditions such as rain, snow, or extremely low temperatures wait times can be much longer. Plan accordingly.