Increased traffic volumes in limited road space led to increased congestion levels on urban roads, especially at intersections. One of the major factors for such increased delays at the intersections is the inability of the traffic signals to respond to the demand fluctuations. An Adaptive Traffic Control System (ATCS) that adapts to the real time fluctuations can improve the intersection performance. However, such a system requires collection and communication of extensive amount of traffic data in real time and is often achieved through installation of location based sensors. Compared to the traditional location-based sensors, advanced sensing technologies such as Wi-Fi scanners are robust, cost-effective, easy to maintain, and works independent of the prevalent traffic conditions. With this motivation, this study focusses on developing an ATCS using sample travel time information from Wi-Fi sensors for homogenous and lane disciplined traffic conditions. The proposed system is based on quantifying the intersection performance in terms of total delay for the current cycle and
adjusting the signal timings for the next cycle to improve signal operation. A mathematical model is formulated using shock waves formed during the red and green phases, to estimate optimal phase durations. The performance of the developed strategy is evaluated with respect to the signal design when entire population data is available. With respect to such a base case, the probe-based model showed a difference of only 3.94% when computed theoretically and
9.61% when implemented in VISSIM. The results revealed that the proposed design is capable of handling traffic flow fluctuations without requiring the entire traffic stream data. The system demonstrated that sample data from four probe vehicles per phase is adequate for real-time optimal signal design. When compared with existing signal design in field i.e., Webster’s design, the proposed model showed 52.55% improvement when computed theoretically and 29.29% when implemented in VISSIM. Therefore, it can be inferred that the proposed signal design yields a better level of service on urban roads relative to the existing
design procedures without collecting the whole traffic stream data. The proposed ATCS system will be extended to incorporate the mixed traffic characteristics, to be suitable for implementation in developing countries with heterogeneous traffic conditions.