NREL completed a geospatial & temporal analysis of telematics data to estimate the fraction of platoonable miles traveled by class 8 tractor trailers. The telematics data set consist of over 57,000 unique vehicles traveling over 210 million miles combined during a two week period in which the vehicles consumed 75% of their fuel in top gear. The data is at a one hour resolution resulting in 22% of miles being driven at an unknown speed. Multiple analysis methods to estimate platoonable miles are discussed. Results indicate that 60-75% of total miles driven at known speeds are at speeds amenable to platooning. Taking into account availability of a nearby partner vehicle going the same direction regional results ranged from 33% platoonable to 71% platoonable. This paper discusses the methodologies used, limitations of large but low time-resolution data sets, and the fuel consumption reduction opportunities from large scale adoption of platooning technology for class 8 highway vehicles in the US.