LOS is calculated using formulas found in the updated Highway Capacity Manual (HCM). Depending on the type of facility (i.e. uninterrupted freeway, two lane rural highway, arterial streets etc.) and number of lanes, the appropriate HCM formula is applied to determine LOS. The formulas use output from the modeling process. Average operating speed, directional volumes, and density output from the model's run combine with basic geometric considerations (level, rolling or mountainous) to automatically calculate and apply the appropriate LOS formula. This simplified approach for planning enabled SCOG to examine critical policy options with greater ease and confidence. Also, we were able to better scrutinize and, in some cases, recommend revisions to previously adopted transportation plans. This new TMODEL2 LOS Module pulls together all previously used analytical output such as V/C ratios into an easy to understand color coded display.

Two very real tests of the new Module came as our Region discussed setting LOS standards for State Routes. One city wanted a higher LOS standard than the other cities. A standoff began brewing. However, in meetings to discuss the issue, SCOG was able to provide LOS forecasts from our Countywide traffic model which showed that the city's LOS standard would be met over twenty years. Even when a key external's traffic volume was bumped up considerably, the LOS standard was met. The new TMODEL2 LOS Module gave us the analytical ability to frame our data to the context at hand. It also allowed us to display our model's output in an easy-to-read and understand format.

The second test of the new Module came as we evaluated the Washington State Highway System Plan for Skagit County. The Plan is a twenty year list of conceptual improvements with costs for State Routes. The Plan forecasted deficiencies by using standardized growth factors. It also listed projected LOS on State Route segments. Using the new LOS Module, SCOG was able to provide LOS forecasts from our model to examine and revise the System Plan. It made the work much simpler and provided common ground for understanding, which helped lead to Regional consensus.

In summary, the new LOS Module is an excellent addition to the TMODEL2 software. It provides for easier understanding of traffic model output, especially as this output moves through the planning process. Most importantly, it is an excellent example of the dedication of the folks at TModel Corp. to serve all of us better!