Transportation
Do you have questions or comments about this model? Ask them here! (You'll first need to log in.)
VERSION
$Id: Transportation.nlogo 37529 2008-01-03 20:38:02Z craig $
WHAT IS IT?
This is a model for Computer HubNet, which simulates traffic and the public policy decisions (and the ramifications of those decisions) that can result from trying to regulate that traffic.
Each participant is a citizen in a small city with one single-lane highway
(taken from the "traffic basic" model) and a train. The train runs at constant speed, set with the TRAIN-SPEED slider. The cars travel as quickly as they can, but will slow down to avoid collisions with cars in front of them. As more cars get onto the highway, the traffic jams become increasingly large and frustrating.
City residents can try to remedy the situation by charging different amounts of money for drivers and rail passengers. How much must they charge in order to reduce traffic to a normal flow, such that driving is faster than taking the train? When this happens, will the city earn more revenue from the train, or from the cars? And how will all of this affect the city's residents, who may not be able to afford driving or the train?
HOW TO USE IT
When the model loads, it will ask you to enter the name by which the model will be known on the network. Enter your name (as it suggests), or perhaps something more descriptive, such as "transportation." Once you have done this, click on the "setup" button. Each participant should then run the "HubNet client" program on their own computer, connecting to the server that you named.
Warning: Clicking on "setup" removes the participants from the system, and forces them to re-connect.
THINGS TO NOTICE
- What is the capacity of the road vs. the train?
- What is the correlation (if any) between the city's income and traffic on the roads?
- Is the city's interest always the same as the individual's interest? Where are they the same? Where are they different? How do the citizens react when faced with such dilemmas?
THINGS TO TRY
- Does the city make more money from cars, or from the train? What settings for car and rail fare will maximize the city's income?
- Make the robots switch modes of transportation based on an algorithm
EXTENDING THE MODEL
- Add a "welfare" option; when someone cannot afford to take the train or drive, they should receive a subsidy from the collected taxes.
- The current model assigns a salary to each individual. But there's no way for people's salaries to rise or fall. Allow individuals to invest some of their money for a potential payoff. Perhaps there could be two kinds of investments, education (where you spend a lot over a long time, and see an increase in your salary) and stocks (where you invest any amount of money over any amount of time, and see a random return in your holdings, but not your salary.
- Add a second highway with a separate (and different) cost. How does this affect traffic? How does this affect the city's income?
- Make the robots intelligent, allowing them to move between driving and the train (like people do). What rules should the robots follow? When should they take the train? When should they drive?
NETLOGO FEATURES
Lots of Computer HubNet stuff
RELATED MODELS
"Traffic basic" (which comes with NetLogo)
CREDITS AND REFERENCES
??? What should I put here ???
Thanks to the following people for help and support: Uri Wilensky, Matthew Berland, Josh Unterman, Sharona Halevy, Dor Abrahamson. (The order of the preceding list of names has nothing whatsoever to do with
TO DO
- Don't use maps as an example in the curriculum
- Make the train stops (and wait-per-stop) adjustable
- Add a more useful info tab
- Can we reduce the information load further?
- Different background color for bankruptcies?
- ptext and ptextcolor for labeling the highway and railway?
- Ask kids to interview their parents about why they travel in a
certain way
- Reduce the information load on the graphs
- Stack the graphs vertically, so that they line up
- Make the clear/setup buttons closer to the HubNet standard, with a
warning if you try to setup with people attached.
- Background colors for the road
- Make train-speed an integer in the slider
Comments and Questions
globals [ road-row rails-row bankrupt-row-max bankrupt-row-min shape-names colors used-shape-colors max-possible-codes
road-money-collected rail-money-collected driver-speed-up driver-slow-down road-color rails-color]
breed [ drivers driver ]
breed [ rail-passengers rail-passenger ]
breed [ bankruptcies bankruptcy ]
turtles-own [ speed speed-limit speed-min user-id money salary color-name]
; ------------------------------------------------------
; Overall setup
; ------------------------------------------------------
to startup
hubnet-set-client-interface "COMPUTER" []
hubnet-reset
end
to setup
set road-row 0
set rails-row -5
set bankrupt-row-min 5
set bankrupt-row-max 6
set road-color violet
set rails-color red
;; The following two variables are taken from the traffic-basic model,
;; where they are sliders available for user modification. Since traffic
;; in this model is affected much more dramatically by cars entering
;; the highway, I removed these from the GUI in the interest of cleaning
;; things up.
set driver-speed-up 100
set driver-slow-down 100
set used-shape-colors []
set shape-names ["wide wedge" "square" "car" "big boat" "pickup truck"
"nu" "uu" "circle" "butterfly" "sheep" "lobster" "monster"
"moose" "bear" "teddy bear"]
set colors [ gray brown green lime turquoise
cyan sky blue violet ]
set colors remove road-color colors
set colors remove rails-color colors
set max-possible-codes (length colors * length shape-names)
ask patches [ setup-road ]
setup-car-robots
ask patches [ setup-rails ]
setup-rail-robots
; Get rid of bankrupt robots
ask bankruptcies with [user-id = 0] [die]
; Bankrupt users some money again
ask bankruptcies with [user-id != 0] [ driver-to-onramp ]
ask turtles [
set money int random-normal initial-money-mean initial-money-sd
set salary int random-normal individual-salary-mean individual-salary-sd
if salary < 0 [ set salary 0 ]
]
set-current-plot "Wealth distribution"
histogram [ money ] of turtles
end
to setup-road
if ( pycor = road-row ) [ set pcolor road-color ]
end
to setup-rails
if ( pycor = rails-row ) [ set pcolor rails-color ]
end
;; pick a shape and color for the turtle
to set-unique-shape-and-color
let code 0
set code random max-possible-codes
while [member? code used-shape-colors and ((count drivers + count rail-passengers) < max-possible-codes)]
[
set code random max-possible-codes
]
set used-shape-colors (lput code used-shape-colors)
set shape item (code mod length shape-names) shape-names
set color item (code / length shape-names) colors
if color = gray [set color-name "gray"]
if color = brown [set color-name "brown"]
if color = yellow [set color-name "yellow"]
if color = green [set color-name "green"]
if color = lime [set color-name "lime"]
if color = turquoise [set color-name "turquoise"]
if color = cyan [set color-name "cyan"]
if color = sky [set color-name "sky"]
if color = blue [set color-name "blue"]
if color = violet [set color-name "violet"]
end
; ------------------------------------------------------
; Set up drivers (cars)
; ------------------------------------------------------
to setup-car-robots
if ( initial-car-robots > world-width )
[
user-message (word "There are too many drivers for the amount of road. Please decrease the INITIAL-CAR-ROBOTS slider to below " (world-width + 1) " and press the SETUP button again. The setup has stopped.")
stop
]
; Get rid of existing car-robots
ask drivers with [user-id = 0] [die]
create-drivers initial-car-robots [
setup-generic-robot
set ycor road-row
separate-drivers
]
end
; this function is needed so when we click "Setup" we
; don't end up with any two drivers on the same patch
to separate-drivers ; turtle procedure
if any? other drivers-here
[ fd 1
separate-drivers ]
end
; this function is needed so when we click "Setup" we
; don't end up with any two drivers on the same patch
to separate-bankruptcies ; turtle procedure
if any? other bankruptcies-here
[ set heading 90
fd random 5
separate-bankruptcies
]
end
to setup-generic-robot
set xcor random-float world-width
set heading 90
set speed 0.1 + random 9.9
set speed-limit 1
set speed-min 0
set salary int random-normal individual-salary-mean individual-salary-sd
if salary < 0 [ set salary 0 ]
end
; ------------------------------------------------------
; Go!
; ------------------------------------------------------
to go
let old-shape 0
move-cars
move-train
;; ---------------------------------------
;; Check for bankruptcies
ask turtles with [ money <= 0 and (ycor = road-row or ycor = rails-row) ]
[
set old-shape shape
set breed bankruptcies
set shape old-shape
set ycor bankrupt-row-min + random (bankrupt-row-max - bankrupt-row-min + 1)
set speed 0
set money 0
separate-bankruptcies ]
;; Pay a salary to everyone on the right side of the screen
ask turtles with [ xcor + speed > (max-pxcor + 0.5) ]
[ set money money + salary ]
set-current-plot "Wealth distribution"
histogram [ money ] of turtles
;; ---------------------------------------------
while [hubnet-message-waiting?]
[
hubnet-fetch-message
ifelse hubnet-enter-message?
[ create-entering-driver ]
[
ifelse hubnet-exit-message?
[
ask turtles with [user-id = hubnet-message-source] [ die ]
]
[
if hubnet-message-tag = "method-of-transportation"
[
if hubnet-message = "Drive"
[ rail-passenger-becomes-driver hubnet-message-source]
if hubnet-message = "Take the train"
[ driver-becomes-rail-passenger hubnet-message-source]
]
]
]
]
tick
;; Send info to the client window
hubnet-broadcast "View" "View"
hubnet-broadcast "Cost to drive" driver-cost
hubnet-broadcast "Cost of train" train-cost
ask turtles with [ user-id != 0 ]
[
hubnet-send user-id "Your savings" money
hubnet-send user-id "Your salary" salary
ifelse breed = bankruptcies
[ hubnet-send user-id "You are a" (word "bankrupt " color-name " " shape) ]
[ hubnet-send user-id "You are a" (word color-name " " shape) ]
]
if ticks mod plot-frequency = 0 and any? drivers
[ set-current-plot "Commuters"
set-current-plot-pen "Bankruptcies"
plot count bankruptcies
]
end
;; Client Message Processing Procedures
to listen-clients
end
to create-entering-driver
create-drivers 1 [driver-to-onramp
set user-id hubnet-message-source
set-unique-shape-and-color
set money int random-normal initial-money-mean initial-money-sd
set salary int random-normal individual-salary-mean individual-salary-sd
if salary < 0 [ set salary 0 ]
]
end
to move-cars
;; Drivers have two possible headings, 90 (on the road) and 180 (waiting to get
;; on the road). If you're on the road, then try to move forward. If you're
;; waiting to get on the road, then you have to wait for an opening.
ask drivers [
ifelse (heading = 90)
;; If heading is 90, then we are driving. Set the car's
;; speed according to the car ahead of it, speeding up if no
;; one is there (and slowing down to match the car's speed
;; if someone is there).
[ifelse any? drivers-at 1 0
[ set speed ([speed] of one-of drivers-at 1 0)
slow-down-driver ]
[ speed-up-driver ]
if speed < speed-min [ set speed speed-min ]
if speed > speed-limit [ set speed speed-limit ]
fd speed
;; Charge everyone at the right side of the screen
if xcor + speed > (max-pxcor + 0.5)
[ set money money - driver-cost
set road-money-collected road-money-collected + driver-cost
]
]
;; If heading is not 90, then it is presumably
;; 180, which means that it is waiting to enter the road.
;; If there are no cars at the entry point, then
;; everyone moves forward, and the bottommost turtle
;; turns to have a heading of 90, like other cars on the road
[if (not any? drivers-at 0 -1)
[fd 1
lt 90]
]
]
plot-drivers
end
to move-train
ask rail-passengers
[ set speed (train-speed / 10)
fd speed
;; Charge everyone at the right side of the screen
if xcor + speed > (max-pxcor + 0.5)
[ set money money - train-cost
set rail-money-collected rail-money-collected + train-cost ]
]
plot-rail-passengers
end
to slow-down-driver
set speed speed - ( driver-slow-down / 1000 )
end
to speed-up-driver
set speed ( speed + ( driver-speed-up / 10000 ) )
end
to plot-drivers
if ticks mod plot-frequency = 0 and any? drivers
[
set-current-plot "Commuter Speed"
set-current-plot-pen "Max Driver Speed"
plot (10 * (max [speed] of drivers))
set-current-plot-pen "Average Driver Speed"
plot (10 * (mean [speed] of drivers))
set-current-plot "Commuters"
set-current-plot-pen "Drivers"
plot count drivers
set-current-plot "Money collected"
set-current-plot-pen "Cars"
plot road-money-collected
]
end
to add-car-robot
ifelse (count drivers >= ( 2 * world-width))
[ user-message "You have reached the max number of drivers"]
[ create-drivers 1 [
set money int random-normal initial-money-mean initial-money-sd
set salary int random-normal individual-salary-mean individual-salary-sd
if salary < 0 [set salary 0]
driver-to-onramp
]
]
end
to driver-to-onramp ;; turtle procedure
let old-shape 0
set old-shape shape
set breed drivers
set shape old-shape
set heading 90
set xcor (min-pxcor)
set ycor 1
set speed 0
set speed-limit 1
set speed-min 0
separate-drivers
rt 90
end
; ------------------------------------------------------
; Set up the rail-passengers
; ------------------------------------------------------
to setup-rail-robots
if ( initial-rail-robots > world-width )
[
user-message (word "There are too many rail-passengers for the amount of road. Please decrease the INITIAL-RAIL-ROBOTS slider to below " (world-width + 1) " and press the SETUP button again. The setup has stopped.")
stop
]
; Get rid of existing rail-robots
ask rail-passengers with [user-id = 0] [die]
create-rail-passengers initial-rail-robots [
setup-generic-robot
set ycor rails-row
separate-rail-passengers
]
end
; this function is needed so when we click "Setup" we
; don't end up with any two drivers on the same patch
to separate-rail-passengers ; turtle procedure
if any? other rail-passengers-here
[ fd 1
separate-rail-passengers ]
end
to add-rail-robot
ifelse (count rail-passengers >= world-width)
[ user-message "You have reached the max number of rail-passengers"]
[ create-rail-passengers 1 [
set xcor (min-pxcor)
set ycor rails-row
set heading 90
;; We don't really care about these variables
set speed 0
set speed-limit 1
set speed-min 0
separate-rail-passengers
]
]
end
to plot-rail-passengers
if ticks mod plot-frequency = 0 and any? rail-passengers
[ set-current-plot "Commuter Speed"
set-current-plot-pen "Train Speed"
plot train-speed
set-current-plot "Commuters"
set-current-plot-pen "Rail Passengers"
plot count rail-passengers
set-current-plot "Money collected"
set-current-plot-pen "Train"
plot rail-money-collected
]
end
; ------------------------------------------------------
; Get rid of a robot driver
; ------------------------------------------------------
to remove-one-car-robot
let car-robots 0
set car-robots drivers with [user-id = 0]
if (any? car-robots)
[ ask one-of car-robots [ die ] ]
end
to remove-one-rail-robot
let rail-robots 0
set rail-robots rail-passengers with [user-id = 0]
if (any? rail-robots)
[ ask one-of rail-robots [ die ] ]
end
; ------------------------------------------------------
; Allow people to switch
; ------------------------------------------------------
to driver-becomes-rail-passenger [target-user-id]
let old-shape 0
ask drivers
[ if user-id = target-user-id
[ set old-shape shape
set breed rail-passengers
set shape old-shape
set ycor rails-row
set heading 90
separate-rail-passengers
]
]
end
to car-robot-to-rail-robot
let car-robots 0
let old-shape 0
set car-robots drivers with [user-id = 0]
; Choose a random driver
if (any? car-robots)
[ ask one-of car-robots
[
set old-shape shape
set breed rail-passengers
set shape old-shape
set ycor rails-row
set heading 90
separate-rail-passengers
]
]
end
to rail-passenger-becomes-driver [target-user-id]
ask rail-passengers
[ if user-id = target-user-id [ driver-to-onramp ] ]
end
to rail-robot-to-car-robot
let rail-robots 0
set rail-robots rail-passengers with [user-id = 0]
; Choose a random rail-robot
if (any? rail-robots)
[ ask one-of rail-robots
[ driver-to-onramp]
]
end
There are 2 versions of this model.
Attached files
No files
This model does not have any ancestors.
This model does not have any descendants.
Download this model