Odysa ® Experiences with an individual “green wave” Marcel Willekens / Arjan Bezemer / Kristiaan Langelaar
Summary How does Odysa work? What are the effects? Points of attention References Further developments
Idea behind Odysa ® Efficiency of a green wave is influenced by: Distances between intersections Speed of the vehicles Diffusion of a peloton Number of intersections Traffic flow versus capacity of intersections Traffic flow versus capacity of the network
Idea behind Odysa ® Reward ‘good’ behavior Optimalisation Flow by DYnamic and individual Speed Advice Destroyed speed camera by angry drivers
How does Odysa ® work? Bundle traffic flows (no more diffusion) Green times opposite main directions can fit better in green wave Because of dynamic speeds, also other (secondary) directions can benefit With Odysa you get more control over traffic flow
How does Odysa ® work?
Speed advice based on: Time of the day The car in front of you Your place in the group Your place on the road Possible congestion next intersection
How does Odysa ® work? Sometimes no green wave: If you have to drive too slow (below 50 km/h*) If you have to drive too fast (above 80 km/h*) * Minimum and maximum speed is based on the legal maximum speed and road profile
How does Odysa ® work? Sometimes no advice: Program switch Congestion next intersection Incidents, like accidents etc. Odysa system down or switched off
What are the effects? Flow Safety Pollution Awareness
Effects on the flow
Profile of an average trip (City of Amsterdam network over approx m. and 4 intersections Not coordinated variable cycle time ODYSA
Effect on flow (Amsterdam) Average number of vehicles. Driving time not coord.var. cycle time Driving time ODYSA Difference West -> East (into city) s217 s- 91 s East-> West (out of city) s250 s+ 34 s Crossing network (south - north at intersection 891) s70 s+ 14 s Crossing network (north - south at intersection 891) s116 s+ 21 s Results simulation study morning traffic hour (source: city of Amsterdam)
Effect on flow Public transport –Compared to the situation of absolute priority for public transport in mode “Not coordinated variable cycle time”, absolute priority for public transport in mode Odysa is limited –Extra delay for busses when there is a bus stop within the green wave –Public transport can also profit of green wave
Effects on safety No study has been conducted yet, but the first impressions are: –Less head tail collisions –Lower average speed within green wave Odysa is also applicable in the night with low traffic flows; –excessive speeding is avoided –driver is rewarded with guaranteed green when following the advised speed
Effects on air pollution Real time emission measurements were carried out with a petrol fueled car under different circumstances and routes Measurements were repeated multiple times in a laboratory environment
Effects on air pollution Emissions Nitrogen (NO x ) Emissions Carbon dioxide (CO 2) Emission nitrogen (NO x ) year basis between 06:00 am en 20:00 pm main directions Nitrogen Kg / year Not coordinated variable cycle time ODYSA Emissions carbon dioxide year basis between 06:00 am en 20:00 pm main directions Carbon dioxide x 1000 kg / year Not coordinated variable cycle time ODYSA
Effects on air pollution Emissions (preliminary results) 75% 80% 85% 90% 95% 100% Emissions PM10 (grams / km)Emissions NOx (grams / km) Emissions CO2 (grams / km) Not coordinated variable cycle time Traditional green waveODYSA
Effects on air pollution Lower emissions for traffic on non main directions, although higher travel times Air pollution benefits can be much higher for trucks Emission differences for the whole network are smaller Conclusions:
Awareness Drivers adapt quickly to speed advice Perception research in Odysa Breda : –Traffic on main route is more positive then local traffic; –Truck drivers are more positive then car drivers; –71% of main traffic and 87% of truck drivers obey the advised speed. –Local traffic doesn’t always benefit from Odysa and is less positive.
Points of attention Maximum speed between 70 and 80 km/h; Low percentage local traffic; Over saturated situations on main directions should be avoided at all times; Reliable communication between traffic controllers and (variable) speed indicators; Functional maintenance: green waves need monitoring because of changing traffic flows.
Reference projects Odysa Breda – Tilburg (N282)- 4 intersections (approx meters) Odysa Amsterdam - 4 intersections (approx meters) New Odysa networks in 2009: –expending network Amsterdam from 4 to 6 intersections (approx meters); –Veghel (N279) - 6 intersections (approx meters); –Spijkenisse (N218) - 3 intersections (approx meters); –Eindhoven - 5 intersections (approx meters. This Odysa network includes a new study project “Odysa In-car” where the speed indication is displayed inside the car via a wireless network.).
Developments New software development In-car technology: –Communication from traffic light controller to the car; –Communication from the car to the traffic light controller; –Possible controlling motor management??
In short With Odysa: more control on traffic flows cleaner air less stress for drivers