This paper presents a novel algorithm for vehicle localization and map-matching using particle filter with the help of digital maps. Probability of being on a certain area of digital map according to vehicle speed is used in conjunction with routing information to augment likelihood function in weight calculation step of particle filter. Real life tests were conducted on different regions of Istanbul to test the performance of the algorithm. Test results show dramatic increase in correctness of map-matching and position correction. Algorithm also helps dead reckoning when GPS data is not available temporarily. A simple GPS receiver is fused with odometer data during tests. Expensive sensors are not used to achieve better price/performance for commercial usage.