This study tries to define the effects of navigation systems in urban traffic through city area in İzmir, using Google maps. Navigation systems, especially with real-time traffic data is relatively new, and user's rate has been sharply increased along with a spread of smartphone. However, there is no deep understanding of the navigation systems, yet. Therefore, people who utilize navigation systems while driving might trigger unexpected merits and demerits. The study is conducted on two different scales; (1) commuting trips in the overall city (16 km in a straight line) and (2) short trip in the central business district (2 km in a straight line). Within the study area, the hypothetical trips are generated and the data of travel time and a travel distance of each trip suggested by Google maps is gathered. Compared the data, it is defined that how much time could be saved and how long additional travel distances are caused by Google Maps. Besides, the possible problem in the local streets is investigated. In a narrow local street, the environment should be pedestrian-friendly and suitable for low-speed vehicles, however, navigation systems would lead drivers into the local street. We discover how long are local streets used by the recommendation of the navigation system. The result shows that during peak hours, the travel time travel distance is longer compared to the off-peak hours. Also, it indicates that by using Google Maps, drivers could save travel time while they drive the longer travel distance during peak hours.