History and city revenue
L.C. Clemmer, a 90-year-old Baldwin Park area resident, told me last week how in the late 1930s, the West Covina chief of police decided to slow down traffic on what was then-Garvey Avenue (now the 10 Freeway). So for the portion that was in chief's jurisdiction, the speed limit became 25. Outside of the area, it was 45. The state eventually got involved, but not after four years of revenue from tickets filled city coffers. Pretty ingenious, methinks.