Here you have an introduction to the model.
The image below is a static picture of the simulator (GIS applets still do not work in remote), but you can find the code
here and run it in your computer (NetLogo 4.1.3 suggested).
powered by NetLogo
view/download model file: traffic_and_pollution_in_torino.nlogo
This model uses GIS extension in order to simulate traffic in the city of Torino (Italy) and it shows how traffic conditions influence pollution in the city; in addition it is possible to approximate the amount of money lost due to traffic delays.
Patches not intersecting the GIS represent streets and, of course, turtles (cars) can only move on these patches. Turtles are expected to "drive" on the right, speed is represented by the number of patches they go forward and it decreases if there are any other turtles ahead.
Each patch has an indicator of its pollution levels depending on the number of cars on it and pollution diffuses to other patches as time passes.
Each turtle shows speed, waiting time and motion time.
First of all setup allows to import the GIS, then it is possible to move on the map and choose different areas of the city of Torino; there is a zoom utility but it is recommended to set zoom between 0.05 and 0.08 before going on.
Display-streets-in-patches (a bit slow) makes the distinction between streets and buildings, while draw-streets draws roadways. Notice that it is possible to open or close parts of a street using close-street-here and open-street-here.
Setup-cars creates the selected number of turtles and Go makes them move.
Two buttons allow to follow one of the turtles and to change color to its path.
Two switches allow to consider pollution and to show its concentration on the map; notice that original colors can be brought back using cancel-colors.
Change-street-color makes streets fade at car passage.
It is advisable to follow this order in pressing buttons:
setup / display-streets-in-patches / draw-streets / setup-cars / go.
Sliders:
cost-of-working represents the average cost of an hour of work (in euros or dollars)
poll-dispersion, if positioned at 1.00 no pollution is dissipated, if positioned at 2.00 50% of pollution disappears
The pollution growth caused by cars is represented by a normal probability distribution with parameters pollution-mean and deviation-mean
SantaFeStreets model -- http://backspaces.net/wiki/NetLogo_Bag_of_Tricks#NetLogo_GIS
Traffic Grid model -- Netlogo Library
;;;;;;;;;;;;; LUCA ALASIO - Scuola di Studi Superiori dell'Università di Torino ;;;;;;;;;;;;;;;;;;;
extensions [gis]
globals [
torino ;; GIS dataset
streets ;; patches representing streets
center-x ;;
center-y ;; center of the map
roads ;; patches representing roadways
mean-poll ;; average pollution indicator
mean-wait-time ;; average time turtles stay at rest
mean-motion-time ;; average time turtles stay in motion
mean-speed ;; turtles'speed indicator
total-cost ;; cost of time spent waiting
]
patches-own
[
street? ;; true if the patch is part of a street.
color-p ;; indicates right hand traffic
turtles-num ;; number of turtles on the patch
pollution ;; amount of pollution on the patch
]
turtles-own
[
speed ;; the speed of the turtle
wait-time ;; the amount of time since the last time a turtle has moved
motion-time ;; the amount of time with positive speed
color-c ;; indicates right hand traffic
]
;; WORLD ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
to setup
clear-all
ask patches [set pcolor white]
set torino gis:load-dataset "torino/file.shp"
draw
end
to draw
clear-drawing
setup-world-envelope
gis:set-drawing-color gray + 1 gis:draw torino 1
end
to setup-world-envelope
gis:set-world-envelope gis:envelope-of torino
let world gis:world-envelope
let x0 (item 0 world + item 1 world) / 2 + center-x; center
let y0 (item 2 world + item 3 world) / 2 + center-y
let W0 zoom * (item 1 world - item 0 world) / 2 ; half-widths
let H0 zoom * (item 3 world - item 2 world) / 2
set world (list (x0 - W0) (x0 + W0) (y0 - H0) (y0 + H0))
gis:set-world-envelope world
end
to center-here
while [not mouse-down?] [wait .01]
set center-x center-x + (mouse-xcor * gis-patch-size)
set center-y center-y + (mouse-ycor * gis-patch-size)
draw
end
to-report gis-patch-size ;; note: assume width & height same
let world gis:world-envelope
report (item 1 world - item 0 world) / (max-pxcor - min-pxcor)
end
to zoom-in set zoom max list .01 precision (zoom - .1) 2
draw
end
to zoom-out set zoom min list 1.2 precision (zoom + .1) 2
draw
end
to zoom-std
set zoom 0.05
draw
end
to move-right
set center-x center-x + shift * gis-patch-size
draw
end
to move-left
set center-x center-x - shift * gis-patch-size
draw
end
to move-up
set center-y center-y + shift * gis-patch-size
draw
end
to move-down
set center-y center-y - shift * gis-patch-size
draw
end
to display-streets-in-patches
ask patches [ set pcolor black
set street? true ]
ask patches gis:intersecting torino
[ set pcolor white
set street? false ]
set streets patches with [street? = true]
end
;; STREETS ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
to draw-streets-E
ask streets
[ if ( [pcolor] of patch-at 1 0 = white and
[pcolor] of patch-at 1 1 = white and
[pcolor] of patch-at 1 -1 = white
)
[set pcolor red]
]
end
to draw-streets-W
ask streets
[ if ( [pcolor] of patch-at -1 0 = white and
[pcolor] of patch-at -1 1 = white and
[pcolor] of patch-at -1 -1 = white
)
[set pcolor blue]
]
end
to draw-streets-N
ask streets
[ if ( [pcolor] of patch-at 0 1 = white and
[pcolor] of patch-at 1 1 = white and
[pcolor] of patch-at -1 1 = white
)
[set pcolor yellow
]
]
end
to draw-streets-S
ask streets
[ if ( [pcolor] of patch-at 0 -1 = white and
[pcolor] of patch-at -1 -1 = white and
[pcolor] of patch-at 1 -1 = white
)
[set pcolor green]
]
end
to draw-streets ;; set a different color in order to make roadways recognisable
draw-streets-N
draw-streets-S
draw-streets-E
draw-streets-W
set roads streets with [ pcolor != black ]
ask streets [set color-p pcolor]
end
to cancel-colors
ask patches
[ if street? = false [set pcolor white] ]
ask streets
[set pcolor black]
end
;; TURTLES ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
to setup-cars
set-default-shape turtles "car"
create-turtles num-cars
put-on-street
ask turtles [set speed 1]
end
to put-on-street
ask turtles [move-to one-of roads]
end
to go
if poll-flag = true
[
ask streets [set turtles-num count turtles-on self]
evaluate-pollution
]
if plot-flag = true
[ do-plots ]
ask turtles
[
if color-p != black
[set color-c color-p]
let turtles-ahead turtles in-cone 2 45
ifelse any? turtles-ahead
[ slow
rt 7 + random-float 3 ]
[speed-up]
if ([pcolor] of patch-ahead 1 != white) and ([street?] of patch-ahead 1 = true)
[fd 1]
ifelse ([pcolor] of patch-ahead 1 = white) or ([street?] of patch-ahead 1 = false)
[ lt 30 ]
[
ifelse (color-c = [color-p] of patch-at 1 0)
or
(color-c = [color-p] of patch-at 1 1)
or
(color-c = color-p)
[ speed-up
if ([pcolor] of patch-ahead speed != white) and ([street?] of patch-ahead speed = true)
[fd speed]
]
[ rt -15 + random-float 30
speed-up
if ([pcolor] of patch-ahead speed != white) and ([street?] of patch-ahead speed = true)
[fd speed]
]
]
ifelse speed = 0
[ set wait-time wait-time + 1
set motion-time 0]
[ set wait-time 0
set motion-time motion-time + 1]
]
tick
end
to slow
if (speed > 0)
[set speed speed - 1]
end
to speed-up
let turtles-ahead turtles-at 0 1
if ([pcolor] of patch-ahead 2 != white) and (not any? turtles-ahead)
[ set speed speed + 1]
end
to cancel-cars
clear-turtles
set total-cost 0
end
to add-cars
set-default-shape turtles "car"
create-turtles num-cars
ask turtles [set speed 1
move-to one-of streets]
end
;; POLUTION AND PLOTS ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
to evaluate-pollution
ask streets
[
if turtles-num != 0
[
set pollution pollution + abs ( random-normal (turtles-num * pollution-mean) (turtles-num * pollution-deviation) )
]
]
diffuse pollution 0.7
ask patches
[
set pollution pollution / poll-dispersion
]
if show-poll = true
[show-pollution]
set mean-poll mean [pollution] of patches
set-current-plot "Average Pollution"
set-current-plot-pen "mean-poll"
plot mean-poll
end
to do-plots
set mean-wait-time mean [wait-time] of turtles
set-current-plot "Average Wait Time"
set-current-plot-pen "mean-wait-time"
plot mean-wait-time
set total-cost total-cost + (count turtles with [speed = 0]) * (cost-of-working / 3600)
set-current-plot "Waiting Time Cost"
set-current-plot-pen "total-cost"
plot total-cost
set mean-motion-time mean [motion-time] of turtles
set-current-plot "Average Motion Time"
set-current-plot-pen "mean-motion-time"
plot mean-motion-time
set mean-speed mean [speed] of turtles
set-current-plot "Average Speed"
set-current-plot-pen "mean-speed"
plot mean-speed
end
to show-pollution
ask patches
[
if (pollution >= 0)
[set pcolor 10 + pollution * 2 / 3]
]
end
to cancel-plots
clear-all-plots
end
to cancel-pollution
ask patches
[set pollution 0]
end
;; OBSERVATION ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
to inspect-car
inspect turtle 1
ask turtle 1
[set pcolor cyan]
end
to map-car
ask turtle 1
[set pcolor cyan]
end
to cancel-cyan
ask streets
[if pcolor = cyan
[set pcolor black]
]
end
to street-change-color
ask turtles
[ if pcolor < 9
[set pcolor (pcolor + 0.2)]
]
end
to close-street-here
while [not mouse-down?] [wait .01]
let posx mouse-xcor
let posy mouse-ycor
ask patches
[if distance patch posx posy < 2
[set pcolor white] ]
end
to open-street-here
while [not mouse-down?] [wait .01]
let posx mouse-xcor
let posy mouse-ycor
ask patches
[if distance patch posx posy < 2
[set pcolor black] ]
end
;;;;;;;;;;;;; LUCA ALASIO - Scuola di Studi Superiori dell'Università di Torino ;;;;;;;;;;;;;;;;;;;