IAES International Journal of Robotics and Automation (IJRA) Vol. 12, No. 4, December 2023, pp. 373~382 ISSN: 2722-2586, DOI: 10.11591/ijra.v12i4.pp373-382  373 Journal homepage: http://ijra.iaescore.com Traffic lights time strategy for T-junctions of toll road gate Tomi Tristono 1 , Setiyo Daru Cahyono 2 , Seno Aji 2 , Pradityo Utomo 2 , Joko Triono 2 1 Department of Informatics Management, University of Merdeka Madiun, Madiun, Indonesia 2 Department of Civil Engineering, University of Merdeka Madiun, Madiun, Indonesia Article Info ABSTRACT Article history: Received Dec 11, 2022 Revised Apr 8, 2023 Accepted May 28, 2023 Vehicles wishing to pass on the toll road must diverge from the traffic flow on public roads. The toll road movement consists of low vehicles (LV) and heavy vehicles (HV). The public road movement is a mixed traffic flow consisting of LV, HV, motorcycles, and unmotorized vehicles. Traffic lights are used at the T-junction of the toll road gate for travel safety management. The traffic lights that implement a fixed-time strategy should be optimized for efficiency. This study aims to review the safety of travel management at T-junctions for the toll road gate when adaptive traffic lights are used. The structural complexity of mathematical modeling with Petri net is used to analyze and measure the feasibility study. Results illustrate that the structural complexity of the traffic lights that implement a fixed time strategy equals 0.387. It is equal to 0.489 for the adaptive traffic lights. The structural complexity of adaptive traffic lights is 25% higher than conventional systems that implement a fixed-time strategy. The adaptive traffic lights time strategy is feasible for travel safety for road users. The travel time is efficient and comfortable because the delay is low. Furthermore, traffic lights can adjust to the demand of vehicles queuing. Keywords: Adaptive traffic lights Safety of travel management T-junctions Toll road gate This is an open access article under the CC BY-SA license. Corresponding Author: Tomi Tristono Department of Informatics Management, University of Merdeka Madiun Madiun, Indonesia Email: tomitristono@unmer-madiun.ac.id 1. INTRODUCTION The T-junctions are prepared for the gate of the toll road. Therefore, they play a role in providing services for vehicles that will enter the toll road. In addition, vehicles that have ended their travel on the toll road and wish to join the traffic flow on public roads should also pass these T-junctions. The regulations state that the vehicles passing on the toll road are limited. They are low vehicles (LV) and heavy vehicles (HV). The number of vehicles passing on the toll road is small compared to those that pass through on public roads. The vehicles must be road worthy and capable of being driven at high speeds. The existence of vehicles entering the toll road and vehicles leaving the toll road is incidental. They only sometimes exist at every traffic light cycle. The toll road is an intercity freeway [1]. The vehicles flow on public roads is always heavy traffic. Its characteristics are heterogeneous. The mixed movement on public roads consists of LV, HV, motorcycle (MC), and unmotorized vehicles (UM) [2]. It knows that vehicles with different types significantly vary in their static conditions, dynamic behavior, and operating system characteristics [3]. Therefore, when passing on it, the driver must be more patient due to the movement of all vehicles. In addition, they must interact with each other on public roads. Vehicles wishing to pass on the toll road must diverge from the traffic of public roads. Likewise, vehicles have just ended through the toll road and want to rejoin the traffic flow on public roads. Therefore, vehicles entering and leaving the toll road must conflict with traffic flows on public roads. Traffic flow conflicts in different directions can cause congestion, inefficiency, and the potential for accidents [3].