Microsimulation Study for a Motorway in Italy Revealed Cooperative ITS Messages That Inform Vehicles of Route Changes Due to Lane Closures Can Reduce Traffic Delays up to 8.66 Percent.
Connected Vehicle Study Evaluated Queue and Delay for a Two-Lane Italian Motorway with Lane Closure.
Milan, Italy
Roadworks Warning-Closure of a Lane, the Impact of C-ITS Messages
Summary Information
Cooperative Intelligent Transport Systems (C-ITS) are transport systems in which collaboration among two or more ITS subsystems (such as vehicle and roadside) which have the potential to enhance the information flow and consequently the infrastructure capacity. This study presented the potential impacts of a C-ITS implementation in a motorway in Milan, Italy, by mimicking roadworks warning and a subsequent lane closure through microsimulation. The researchers, through their analysis using microsimulation, had the goal of providing feedback to a pilot deployment planned for 2020 for the same Italian motorway used in the simulation.
METHODOLOGY
This study used the A22 Italian two-lane motorway to calibrate and validate a microsimulation traffic model based on recorded data. It recognized variable driver speeds and time gaps in roadwork segments, influenced by the layout. Driving behavior was calibrated for standstill distance, time gap distribution, and longitudinal oscillation. The model featured a cooperative message from a specific link in the network to inform vehicles of route changes. To differentiate Connected Vehicles (CV) from traditional ones, two overlapping connectors under one meter (3.28 feet) long were designed: one for CVs visible from 1500 meters (4921 feet) and another for other vehicles visible from 336 meters (741 feet). Microsimulations were conducted for CV market penetrations from 10 to 100 percent, measuring average speed, delay, vehicle volume, and queue delay upstream of bottlenecks.
FINDINGS
- The results showed that C-ITS messages on lane closures can reduce traffic delays by up to 8.66 percent.
- The results also revealed that the average speed at the roadworks entrance on the closing lane increased by a difference equal to around 10 km/h (6.21 mi/h), while the average time in the queue at the highest market penetration was reduced by 60 seconds on the open lane and 25 seconds on the closing one.
