A nine year record of on-road emission measurements at a West Los Angeles site (La Brea Ave. and I-10) was continued with two additional data collection campaigns in the spring of 2013 and 2015. The University of Denver collected 27,247 (2013) and 22,124 (2015) emission measurements of carbon monoxide (CO), carbon dioxide, hydrocarbons (HC), nitric oxide (NO), ammonia (NH3) and nitrogen dioxide (NO2) from light and medium-duty vehicles. Since 1999 the CO mean emissions have decreased by 82% (70.3 to 13 g/kg), the HC mean emissions by 81% (7.0 to 1.3 g/kg) and the NO mean emissions by 71% (6.6 to 1.9 g/kg). These decreases have happened despite the fact that fleet age has increased by 2 model years as a result of the lost vehicle sales during the 2008 Ã¢â‚¬â€œ 2009 recession. Over the same period the 99th percentiles have dropped by more than a factor of three for CO and HC (773 to 258 g/kg, HC (93 to 24 g/kg) and a factor of 1.5 for NO (53 to 34 g/kg). There are concerns however, that the reductions in the 99th percentiles may be leveling out which would also stall future fleet emissions reductions. These data sets were also used to document that 2009 and newer Volkswagen and Audi diesel vehicles had excessive on-road NO and NO2 emissions.