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Light-Rail Extension in Solna
Integrated model application of Light Rail in Stockholm
2012-03-20
Magnus LindWSP Sverige
Light-Rail: Solnagrenen
• The light-rail extension from Alvik to Solna Station
• Stage 3- Solna Business Park to Solna Station
Frösundaleden – Traffic Flows
40000 f/vmd
19000 f/vmd
7000 f/vmd
26000 f/vmd
16000 f/vmd
Passes Ankdamsrondellen in a tunnel underneath??
Solnagrenen- Frösundaleden
Tvärbanan Frösundaledencost reduction
Minimise Construction works
Trains to cross Ankdamsrondellen at grade
Suggested to cross also Solnavägen at grade instead of grade separated in tunnel
Tvärbanan-Light Rail compared with Trams
Tracks (often) segregated from the carriageway
Higher Capacity and speed then Trams
Absolute priority at signalised junctions
Ankdamsrondellen
Early attempt at design – all arms signalised
Later Design
Absolute priority for the light rail train
The train needs a green light at least 150 meters before the junction
The driver must decelerate to 15 Km/h at a point at least 40 m before the junction
The train needs at least 32 seconds to cross the junciton.
At best, an extension of an existing phase of 21 seconds
At worst, 53 seconds is needed if two trains meet
This results in long red times for movements that are in conflict with the train!
How will the traffic on Frösundaleden be effected?
Can the train be given absolute priority through Ankdams ”roundabout”?
What will be the delay for conflicting traffic flows and will those delays affect the operation of adjacent junctions?
Will the project affect the traffic flows for the whole area?
Methodology
To answer these questions we decided:
To model the network for two future years; 2007 and 2015, using the software Sampers and EMME/2.
The mesoscopic model Dynameq was used to evaluate the effect on the Solna network.
LINSIG was used to find a working layout for the junction and traffic signal designs and to get co-ordinated signal timings for Dynameq and Vissim.
To use a microsimulation model (vissim) to evaluate the final design.
Expanded microsimulation model to evaluate the effects of bus priority on Frösundaleden
DYNAMEQMesoscopic model
DYNAMEQ Network for Stockholm and Solna
DYNAMEQ
The graphical user interface for traffic Signals in DYNAMEQ•Staging•Intergreen times•Green times
LINSIG
Brittish traffic signals model
Models isolated junctions and networks
Can model signalised roundabouts
Can model several signal cycles
Junction coordination
Work flow
SAMPERS/ EMME/2
Distribution of traffic on the Dynameq network
Use traffic flows from DYNAMEQ…
..to optimize the signals network in LINSIG
Put the signal timings back into DYNAMEQ
To get the final traffic flows on the network
LinSig optimised one last time
DYNAMEQ Network 2015With train
• Traffic flow on Gränsgatan halved during peak hour
• +200 through Råsunda
• Saturation rate at 103% on Frösundaleden!
Final Design
Vissim
Vissim was used to evaluate the designs
Conclusions
The different models complement each other: Dynameq good for traffic assignment.
Linsig good for co-ordinated signal timings.
Vissim good for evuation of the detailed design.
The effects of our design descisions quickly become apparant easing the descision making process.
However, any change in the design means you have to update at least two different models.
We havent found any one model that can handle all levels of modeling as well as traffic signal optimisation.
