Replica provides a full set of baseline travel measures that are very difficult to gather and maintain today, including the total number of people on a highway or local street network, what mode they’re using (car, transit, bike, or foot), and their trip purpose (commuting to work, going shopping, heading to school, etc). By updating these measures every three months, Replica also provides the ongoing ability to detect changes in these measures over time?—?helping planners answer questions about land use and transportation from a regional level all the way down to a city block. Replica uses this de-identified data from about 5 percent of the population to learn about travel patterns and create a travel behavior model?—?basically, a set of rules to represent who’s moving where, when, why, and how. But models aren’t perfect. So we gut check these rules using on-the-ground data ) to make sure Replica is consistent with real-world movement patterns.