The California Air Resources Board (CARB) has released the 2018 Base-year Emissions Inventory Report, as required by Senate Bill 1014 (SB 1014, California Clean Miles Standard). (Earlier post.) SB 1014, enacted in 2018, directed CARB and California Public Utilities Commission (CPUC) to develop and implement measures to reduce GHG emissions from Transportation Network Companies (TNCs).

TNCs provide on-demand ride services where rides are arranged online to connect a passenger with drivers using their personal vehicles—e.g., companies such as Uber and Lyft.

As the first step, SB 1014 directed that by 1 January 2020, ARBwould establish a baseline for emissions of GHGs for TNCs for the calendar year 2018 in units of grams of CO₂ per passenger-mile traveled (gCO2/PMT). The newly released report provides information to stakeholders on the base year emissions inventory for TNC operators in California and discusses the assumptions and methodology used to estimate the emissions.

Among the top-level findings and estimates:

• CARB staff estimates that the 2018 TNC vehicle fleet emitted 301 gCO₂/PMT, approximately 50% higher than the statewide passenger vehicle fleet average of 203 gCO₂/PMT.

• The analysis indicates that the industry-wide TNC fleet has a 7% lower passenger occupancy than the California statewide passenger vehicle fleet.

• TNC vehicles operate approximately 61% of its vehicle miles traveled with a passenger in the car; the remaining VMT are deadhead miles.

• The 2018 average fleet occupancy for the TNC industry is 1.55 (an average of the occupancy in “pooled” and “non-pooled” rides) passengers.

• The TNC fleet is relatively more fuel efficient than the California fleet due to having higher fraction of newer model year vehicles and higher percentage of passenger cars versus light trucks.

• Total 2018 TNC fleet electric VMT (eVMT) is about 33.7 million miles—roughly 0.8% of the total VMT generated by the TNC fleet.

• The TNC fleet has a larger fraction of high-mileage hybrid vehicles as compared to the average California passenger vehicle fleet.

Although the vehicles employed by TNCs make up 2.5% of the vehicle population, they are growing at a rapid pace.

Because TNCs operate differently than traditional transportation modes such as buses, trains, or taxis, the impact on future trends of GHG emissions and VMT on a per passenger mile basis is uncertain. At the present time, GHG emissions from the TNC sector is small compared to the total light duty vehicle sector. Nevertheless, we anticipate growth in VMT attributable to TNCs, which necessitates formulation of immediate policies.

—CARB 2018 Base-year Emissions Inventory Report