Abstract
Development of some residential areas around a city generally will develop as satellite city, has become generated traffic for a city. These situations also occur in Purwokerto, the developing city located in South-West Central Java, where the impact to the traffic cause by development of residential areas will be studied in this research. Research was conducted by collecting and analyzing traffic data around Purwokerto. Data collecting include road inventory around area, survey on traffic’s trip generation and attraction, traffic volume survey, inventory of infrastructure and traffic supporting facility in the area of study. Data analysis was conducted by using 4 steps transportation model. Those 4 steps were generated traffic, analysis of traffic distribution, analysis of modal choice and route of traffic, and analysis of traffic impact cause by residential development as well. The survey resulting two residential areascategorized as a big scale area and have second class of traffic impact,while the remaining one residential area categorized as a small scale area and have first class of traffic impact. The rate of trip generation every 100 sq. meters at the peak hour was 7vehicles forresidential area A, 5 vehicle for residentialarea B and C, 2 vehicles for residential area D, and 1 vehicle for residential area E. Developments of residential area have caused improving of traffic volume in the roads around it. The number of the improvement was three roads have VCR (Volume Capacity ratio) value over 0.75 as well and three junctionsalso have VCR over 0.75 and were used for traffic management input. Can be concluded that development of residential area around Purwokerto have significantly impact to the traffic.  
Key words: development; residential; impact; traffic; improvement; VCR