The Real Time Motorist Information System (RTMIS) under development at the University of Washington uses a ratio of Volume to Occupancy with a correction factor (often denoted as "g") to estimate speed. This correction factor is a function of road topology and occupancy. This project will initially produce a value for the correction factor for every pair of loops being used in the RTMIS. It will further produce a correlation between correction factor and occupancy for each set of loop pairs. The correction factor is produced using speed estimates from cross-correlation time delay measurements of on road data.