A serious problem that is always occured over time on the road is a traffic accident. One of the main factors is caused by the volume capacity road. This study aims to determine the factors affecting potential accidents at Ipda Tut Harsono street, the relationship of volume-capacity ratio and the speed of vehicle. Furthermore, this stufy also analyze the relationship of volume- capacity ratio with potential collisions and potential accidents that occur. This analysis uses primary and secondary data. Primary data includes road geometric data, vehicle volume, vehicle speed, side barriers, conflict points and accident occurance. Secondary data includes the population data of Yogyakarta 2016. This analysis uses regression and correlation of analyze with using Ms. Office Excell computer application. The results of this study showed the relationship of volume capacity ratio with vehicle speed on section A and section B with the equation y = (-47,974)x + 56,294 at section A R²= 0.9988 and at section B with the equation Y = (-5,455)x + 55,364 R² = 0.9917. The higher the ratio of volume capacity the lower the speed of vehicle. The relationship of the volume ratio with the potential of collisions at the point of conflict in the unsignalized intersection and at the point of conflict on section B with the equation y = -205,03x² + 255,18x – 37,624 obtained by the value R² at the point of conflict in an unsignalized intersection R² = 0.8532, and at the point of conflict in section B y = (-205,03)x² + 255,18x – 37,624 by R² = 0.7088. With the increase of volume-capacity ratio, the risk of accident occurance in unsignalized intersections and on roads. The condition of volume-capacity ratio of 0.6 to 0.7 has a high number conflict because the driver use to driving with high speed. When the volume-capacity ratio is higher than the 0.8 the driver will slow down due to traffic volume . At the speed of 25-27 km / h volume-capacity ratios of 0.6 to 0.7 there is a high number conflict in unsignalized intersections and at the speed of 26-27 km / h volume-capacity ratio of 0.6 to 0.7 high conflict occurred on section B.