1. An alternative procedure for estimating speed distribution parameters on motorways and similar roads;Ashworth;Transpn. Res.,1976
2. Use of the moving car observer method on one-way roads;Bennett;Traff. Eng. Control,1975
3. A method of estimating the distribution of speeds of cars on motorways;Duncan,1973
4. Graphical solution of moving observer surveys;Hewitt;The Highway Engineer, Journal of Inst. of Highway Engineers,1974
5. A theoretical analysis of the moving observer method;Wright;Transpn. Res.,1973