1. Graduate Research Assistant, Public Policy Center, Dept. of Civil and Environmental Engineering, Univ. of Iowa, 4105 Seamans Center, Iowa City, IA 52242-1527.
2. Associate Professor, Public Policy Center, Dept. of Civil and Environmental Engineering, Univ. of Iowa, 4117 Seamans Center, Iowa City, IA 52242-1527.
3. Bituminous Engineer, Iowa Dept. of Transportation, 800 Lincoln Way, Ames, IA 50010.