Adaptive controlled traffic lights - a progress report from Uppsala Sampo Hinnemo 140429
Table of contents Background Business intelligence Initial system setup (the pilot project) Results so far Expansion of adaptive signal controls General reflections
Background
Increased competitiveness for public transportation In 2008 the Swedish government decided to double the use of public transportation. In order to make this alternative attractive to people two goal were set up: decreased travel time improved regularity The project also intense to decrease CO2 pollution
Business intelligence
Feasibility studies Tests of three systems at Luthagsesplanaden by a traffic simulation software (VISSIM) 0-scenario PRIBUSS Utopia Spot FITS (could not be tested in VISSIM) The focus of the study was peak traffic flows during an ordinary weekday morning. The test showed that the best result was achieved with utopia spot..
Initial system setup (the pilot project)
The pilot project at Luthagsesplanaden Present traffic conditions: 7 traffic signal controlled intersections 16 000 motor vehicles per day 70 buses during peak hour Most bus stops are placed after intersections Two lanes in each direction
Technical structure Central software Traffic optimization Intersection Inductive loop detection
How adaptive traffic controls benefit traffic flow? Adaptive systems benefit traffic flow: Adaptive signal controls take in to consideration all of the intersections and all traffic flow in the network. Buses are detected much earlier. The system can clear congested traffic ahead so buses can be given priority when they arrive to upstream signalized intersections. Sometimes the system packs traffic to enable a green wave later on for more vehicles. The point is to give buses an improved flow through the traffic signals.
Radio communication systems Two radio communications systems are used: INIT (buses in rural traffic) Trivector (buses in city traffic) The interface between the traffic controllers and radio communication receivers consists of I/O expansions cards. The priority messages are sent out in 10 millisecond pulses.
Results so far
Project evaluation Studies before and after The studies were conducted in June 2009 and June 2013. The methods for measuring travel time was: Floating car (travel time for motor vehicles). Data from on board computers in the buses. Data was collected for bus movement between bus stops. (travel time for public transportation). No studies were conducted regarding pedestrians or bicyclists.
Overview Adaptive traffic lights Luthagsesplanaden (Pilot project) Börjegatan/ Kyrkogårdsgatan Daily traffic flow 11 000 motor vehicles Daily traffic flow 16 000 motor vehicles Daily traffic flow 8 000 motor vehicles Uppsala C
Sekunder Reduced travel time for public transportation direction city centre 300 290 Körtider för bussar - Luthagsesplanaden in mot centrum 280 270 Reduced travel time during peak periods 260 250 240 Rick-Göt jun 09 Rick-Göt jun 13 230 220 210 200 06-07 07-08 08-09 09-10 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-18 18-19 Tidpunkt (timme)
Körtider (sekunder) Reduced travel time for public transportation leaving city centre 260 Körtider för bussar - Luthagsesplanaden ut från centrum 250 240 230 Reduced travel time during peak periods 220 210 200 Göt-Rick jun 09 Göt-Rick jun 13 190 180 170 160 06-07 07-08 08-09 09-10 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-18 18-19 Tidpunkt (timme)
Körtider (sekunder) Effect on travel time for cars - main road direction city centre Körtider - Luthagsesplanaden in mot centrum 290,0 270,0 250,0 230,0 210,0 1B 080528-30 1B 130611-13 190,0 170,0 150,0 Kl 08-09 Kl 09-10 Kl 11-12 Kl 12-13 Kl 13-14 Kl 15-16 Kl 16-17 Kl 17-18 Tidpunkt (timme)
Körtider (sekunder) Effect on travel time for cars - main road leaving city centre Körtider - Luthagsesplanaden ut från centrum 290,0 270,0 250,0 230,0 210,0 1A 080528-30 1A 130611-13 190,0 170,0 150,0 Kl 08-09 Kl 09-10 Kl 11-12 Kl 12-13 Kl 13-14 Kl 15-16 Kl 16-17 Kl 17-18 Tidpunkt (timme)
Körtider (sekunder) Effect on travel time for cars - road intersecting main road direction southeast 90,0 Körtider - Kyrkogårdsgatan/Börjegatan in mot centrum 80,0 70,0 60,0 50,0 40,0 2C 080528-30 2C 130611-13 30,0 20,0 10,0 0,0 Kl 08-09 Kl 09-10 Kl 11-12 Kl 12-13 Kl 13-14 Kl 15-16 Kl 16-17 Kl 17-18 Tidpunkt (timme) Medel
Körtider (sekunder) Effect on travel time for cars - road intersecting main road direction northwest Körtider Kyrkogårdsgatan/Börjegatan ut från centrum 120,0 100,0 80,0 60,0 2D 080528-30 2D 130611-13 40,0 20,0 0,0 Kl 08-09 Kl 09-10 Kl 11-12 Kl 12-13 Kl 13-14 Kl 15-16 Kl 16-17 Kl 17-18 Tidpunkt (timme)
Level of service for pedestrians and bicyclists In general the cycle length of the signals have been reduced. Reduced cycle lengths are profitable for pedestrians and bicyclists.
Expansion of adaptive traffic controls
Expansion of adaptive traffic controls Daily traffic flow 16 000 motor vehicles Daily traffic flow 27 000 motor vehicles Daily traffic flow 11 000 motor vehicles Adaptive traffic lights currently operative coordinated systems coordinated systems under construction planning of new systems possible future projects directions for bus priority Daily traffic flow 17 000 motor vehicles
Traffic detectors In the two initial adaptive installations inductive-loop detectors are used for the systems. For the third route new type of detectors will be used: camera detection close to the intersections (long-loops, outgoing spot detectors, pedestrian detection). The intention is to reduce maintenance costs. inductive loops further away from the intersections. Public transports are detected by radio messages/virtual loops
General reflections
General reflections Travel time for public transportation has decreased during peak periods and the reliability of travel time has been improved. During off-peak hours there have not been any significant changes in travel time for public transportation. The system for bus priority as a whole (adaptive control and radio communication) can potentially be improved. The best way to reduce travel time for buses in the future is to calibrate radio communication and to improve maintenance of the radio communication systems. In some cases the GPS-positions where buses send radio messages can be adjusted. Traffic controllers can be programmed to compensate for radio communication delay.
General reflections Camera detection reduces maintenance costs. Cameras are being used more and more and the development is interesting regarding how to make adaptive control more cost efficient.