NetLogo User Community Models
by Klaus G. Troitzsch (Submitted: 01/22/2018)
## WHAT IS IT?
In this model a number of car drivers move around over crossing streets and find their way from their homes to their working places and back. In the beginning they use the right or left lane of the streets in an arbitrary manner. When they meet an upcoming car on the same lane they do not crash but try to find a way to avoid a crash by changing the lane.
## HOW IT WORKS
At every crossroads the car drivers try to use the turn-off which brings them fastest to their destination. When they encounter an upcoming car, i.e. a conflict between right-hand drivers and left-hand drivers, they find out which lane of the street is used by the majority within their vision-range and decide to switch to driving on the other side of the street and continue their way. If this is not possible they turn on the same patch and continue their way in the opposite direction, deciding at the next crossroad which turn-off brings them fastest to their destination.
## HOW TO USE IT
Currently one can only change the number of cars (traffic density) and the range of vision of the car-drivers.
Moreover it is possible to switch between four decision modes:
* ISING: the probability of solving a conflict by changing the preferred lane is a function of the current overall majority.
With `randomise?' switched on, each run starts with a random configuration.
## THINGS TO NOTICE
In most cases all car drivers arrive at their destination and find back home, perhaps several times. After some time a majority of drivers use the same lane, either driving on the left or on the right. How big the majority is and how long it takes all cars to arrive at their destinations depends on the traffic density and the range of vision. The simulation stops 20 time steps after the last conflict.
## THINGS TO TRY
In a large number of simulation runs with different combinations of traffic density and range of vision the dependence of the time until all cars arrived at their destinations and the majority on traffic density and range of vision can be determined.
## EXTENDING THE MODEL
It might be interesting how much the behaviour changes when the road network becomes more complicated.
## NETLOGO FEATURES
## RELATED MODELS
Model 3476 by Carl Edwards is about lane changing for overtaking, not about the emergence of left-hand traffic or right-hand traffic as a legal norm.
## CREDITS AND REFERENCES
The model is mentioned in Klaus G. Troitzsch: Can lawlike rules emerge without the intervention of legislators? (submitted to Frontiers in Evolutionary Sociology
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