eroten
commented
1 week ago Passenger and commercial vehicles. Transit considered in another post
Options for consideration. Will continue to update
Activity/vehicle miles
The current year (2021) inventory uses StreetLight Data to estimate emissions for origin/destination trips between/within counties. StreetLight's earliest available year is around 2017 (differs by mode and exact data source), so that will not get us to 2005.
- Statewide data, scaled to the region based on population. Could do some sort of time series of population growth over time. This would be very coarse.
- Climate Watch
- EPA National Emissions Inventory (NEI), interpolating missing data years
- National Household Travel Survey NHTS, also NextGen editions
- Get MnDOT/WisDOT VMT (interpolate MN 2015 missing data) back to 2005. Obtain data with highest granularity possible, aggregate as needed.
- Run StreetLight analyses for all available years at county and city levels. Compare directly with DOT VMT values and see if there is a consistent value we can use to scale the VMT estimates to match StreetLight estimates
- Potential modeling opportunities based on: centerline miles by route system or functional class, population, employment, population density,
- Major drawback is that we would only have maybe 6 years of StreetLight data to compare to.
- Use LODES LEHD, back to 2002, to estimate or validate VMT values using the Origin-Destination framework.
- LODES is very focused on employee travel. We would have to adjust for this somehow.
The StreetLight Conundrum
(long summary of ongoing discussion with @pawilfahrt)
The Issue with StreetLight is that their sample does not exist prior to 2016. However, their unique advantage is that they give us origin – destinations data for any given geography (with enough a large enough sample size). This enables us to get much more granular and detailed information about the trips that individual people and trucks are making, particularly in regards to trips that start and end within a single jurisdiction.
So for matters when we are trying to offer information to cities, street light is going to be the most nimble and personalized option available. However, for a regional total tally of all of the emissions emitted, a more generalizable data source like the EPA NEI, MOVES, or other data source will be more useful.
The we use StreetLight for reporting in the PCAP we may need to use a different data source for the CCAP. This will require careful consideration and messaging, particularly because it will change the overall emissions estimate. We could offer city level data on a case by case basis for jurisdictions in our region that are interested, but we may not publish these, so we don't have conflict in our publish that are interested, but we may not publish these, so we don't have conflict in our published materials.
IF we want to provide a technical assistance product for cities as they start comprehensive plans in early 2026, we will need to have a tool ready for them by Fall 2025.
Emissions factors
Historical emissions factors should account for how the regional fleet has changed over time. Vehicles are newer, which means they are more efficient. We should(?) see the grams per mile value decrease over time.
- Historical MOVES time series? Dennis says that we will be missing a lot of data if we use MOVES to back-cast
- EPA GHG Hub values (annual, back to 2011)
Identify data sources for 2005 transportation emissions