As mobile phones have the ability to act as participatory sensors, we are beginning to witness the popularity of crowdsourcing and the sharing of traffic reports to improve the quality of the driving experience. This paper presents the architecture and implementation of a system called Social Vehicular Navigation (SVN), which allows users to generate and share geo-tagged image traffic reports called NaviTweets. Based on these traffic reports, Traffic Digests (concise snapshot summaries on the route of interest) are delivered to drivers to provide rich and reliable information supporting the route choice. These digests will complement factors such as the estimated travel time and assist the driver on their route choice decision making. The paper presents the initial design, along with a prototype implementation running on the Android platform, and details a user study conducted to evaluate the influence of providing traffic images on route-choice behavior.