1. Modeling Mobile Emissions with the FME Problem –BC Ministry of the Environment Need to determine emissions from mobile sources –Exact quantity and location unknown – derive surrogate emissions from model –Surrogate emissions estimated from spatially distributed data that should be good indicators of emissions activities –Population –Traffic Volumes –Fuel Sales

2. Modeling Mobile Emissions with the FME Problem Here is the kicker –Population »Census Tract Information »In BC an area can have a concentrated population with a large area of low or no population density –Traffic Volumes »Ministry of Transportation collects data at busy intersections around the province »Large areas of the road network unmonitored –Fuel Sales –Point based – tied to postal areas –You may buy your fuel in Vancouver – and then drive to Kamloops – so can be misleading And finally –Map the surrogate emissions onto the road network for BC –Each segment will the have a contribution from each of the surrogate emissions sources

4. Under-allocation

5. Modeling Mobile Emissions with the FME Solution Map Area, Point and Line Based Surrogates onto a Single Uniform Grid Look after under-allocation –Road Lengths –Unused Grid Cells –Flood back into road network Accept that we are only making an estimate –Note all assumptions and simplifications –Document how to remove or improve on them in the future