The Hsuehshan Tunnel or "Snow Mountain" tunnel, is the longest tunnel in Taiwan. The main road connects the city of Taipei to the northeastern county of Yilan. Travel times can take from 30 minutes to up to 2 hours. The challenge is to decrease travel time during busy periods. We used data provided by the Taiwanese government: Column Description for Traffic XML Coordinate Information (WGS84) for Traffic Data CSV We analysed this data in order to offer an engineering and a software based solution.
The Hsuehshan Tunnel primarily has two, sometimes three, lanes traveling in both directions and three to four in/out links in both directions. The provided data covers 30.2 km. The throughput of the tunnel is 3600 cars per hour in both directions. Based on the data we have created two charts. The first, average speed and the second, intensity of traffic flow, both factored by days of the week.
The two charts show that the highway has the same intensity in both directions, but the travel time and the congested time to Taipei lasts much longer. Based on those charts we can define critical points for traffic flow.
We designed an app which visualizes traffic flows in order to better understand the reasons for a decreasing of average speeds. The app provides data, represented visually, which anyone can use to make a more informed decision about their commute.
iOS (prototype for iPhone) Size of the app: 1MB Description: Visualizes historical data from April to June and shows the average speed for the current day of the week and a current average speed of the entire simulation.
The app highlights the main problem, a decrease in speed on the way to Taipei. A big contributing factor are the first 10-15 km in the beginning of the highway when the cars are in the tunnel. During this point speed can fall down to 5-10 km/h at times. Solutions to this problem are not as easy as they may seem because the highway is completely busy in both directions. Simply reversing the lanes wouldn't work and using secondary roads isn't an option, because they take much longer to reach Taipei. We suppose that the engineering solutions below could improve the traffic situation: - These changes will prevent phantom traffic jams - During congested times from Taipei, the speed in the tunnel should be changed manually to 60 km/h - During very congested times from Taipei the speed should be changed to 60 km/h throughout the whole highway - During very congested times to Taipei the speed should be changed to 40-50 km/h in the tunnel. - There should be signs to keep distance and no passing. - Based on the information from flow detectors one could build an automatic system for changing the speed limit at different parts of the highway and especially in the tunnel. - Unfortunately there is no solution for this problem based on redistributing car flows throughout the day, because the highway is overloaded with cars for many hours in a row. In this case limitation by even and odd numbers of license plates for very congested times, every week, can improve speed flows and push people to use public transport more. This rule applies only for private small cars.
Using this application people could also see what the current situation is and how it has been historically, possibly suggesting a better time to commute
Whats next? One or more of the solutions, engineering or software, could be implemented. The app could be augmented by real time data and gamification. In gamification people can receive points by solving problems all together and improving traffic situations. For example, involving more people in the app and following recommendations gives you points, which in turn improves traffic flow and gives users satisfaction for their involvement.