Colleagues, Elaine Murakami at FHWA has suggested I contact you. I am working on a county-to-county work flow analysis for North Carolina's 100 counties, and am interested to know if anyone is/has done something similar for cities or for other states or US regions. The issues we are addressing are: 1. Has inter-county commuting increased as a share of trips, VMT, and fuel use since 1990? 2. What percent of state travel and fuel use is in intra- and inter-county commuting? Is it a declining or increasing share? My student (Ellen Cervera) has completed the first phase of her work, for 2000, and is beginning the 1990 analysis. Her problem involves computing, for all NC co-to-co flows (100*100), the % of vehicle trips (adjusted for carpooling), the % of VMT (using a distance matrix and 20 % road circuituity), and % of fuel use (using weighted fuel rates from Hy Statistics VM-1) that is inter-co versus intra-co; also these %'s as a function of total state use, and changes in these %'s from 1990 to 2000. The effects are hypothesized to be compensating: that is, trips are getting longer and the % of travel that is inter-county is increasing, but fuel use is declining per mile, so the magnitude of fuel use in inter-county may be stable or declining over time. My modeling system is TransDAD (http://www.caliper.com) Anyone working on a similar problem with the 2000 county-to-county data? We would appreciate receiving materials at this location or at fax 704-687-3442. Thanks Prof. David T. Hartgen UNC Charlotte 704-687-4308