Tools for Understanding Highway Performance


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Documentation for package ‘cartools’ version 0.1.0

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A B C D F G H L M N P Q R S T U V X Z

-- A --

acceldown The 'acceldown' function estimates the relative locations of a vehicle downstream of a bottleneck.
accelpass The 'accelpass' function estimates the relative locations of two vehicles where one passes the other.
animate_rr 'animate_rr' draws the path around the ring-road using data 'LF' from 'rrtrials'.

-- B --

bmfree The 'bmfree' function returns a 'tux' matrix of time 't', speed 'u' and location 'x' values.
bmfree2 The 'bmfree2' function returns a 'tux' matrix of time 't', speed 'u' (fps) and location 'x' (feet).
brkcross0 'brkcross0' estimates the time, speed and location that a vehicle crosses bottleneck location 'x' = 0.
brkdelay 'brkdelay' is a wrapper function for 'brktrials2'.
brkdelay3 'brkdelay3' is a wrapper function for 'brktrials3'.
brksummary The function 'brksummary' is a wrapper for 'accelpass' and 'passplot'.
brktrials2 'brktrials2' produces 't-x' trajectories for lead and following vehicles at a bottleneck
brktrials3 'brktrials3' produces 't-x' trajectories for lead and following vehicles at a bottleneck
brktrials3setup 'brktrials3setup' produces 't-x' trajectories for lead and following vehicles at a bottleneck

-- C --

capacityplot The function 'capacityplot' creates a '(k,Q*)' plot indicating the success rate of sustaining capacity 'Q*'
cfanim 'cfanim' uses a stochastic model of speed to describe driver's ability to maintain a speed 'u'.
crossconflict The function 'crossconflict' a graph showing driver conflict of two vehicles changing lanes.

-- D --

decelmerge The 'decelmerge' function estimates the relative locations of two vehicles where one passes the other.
dfmanager 'dfmanager' is a wrapper function for 'brktrials2'

-- F --

f1 Space headway 'h' between the lead and following vehicles at time 't'. Lead and following vehicles use 'gbm' and constant speed models, respectively.
f2 Headway 'h' between the lead and following vehicles at time 't'. Lead and following vehicles use constant speed models, respectively.
findt1 'findt1' returns the deceleration time 't1', the location 'xf1', and speed 'uf1' of the following vehicle at time 't1'.
findt1ab The 'findt1ab' returns the time 'tf1' and the location 'xf1' and speed 'uf1' of the following vehicle when the driver begins to decelerate.
findt2 'findt2' returns the time 't2' and 'xf2' when the following vehicle driver recognizes the lead vehicle has decelerated.
findt2ab 't2' is the intersection point of the following driver sight-line and lead vehicle 'x' trajectory. Lead vehicle location 'xl2' and speed 'ul2' at the intersection point, respectively.
findt5 The time 't5' when the following vehicle reaches the bottleneck or location 'x' = 0.
findt5ab The time 't5' when the following vehicle reaches the bottleneck or location 'x' = 0.
formqueue The 'formqueue' function is used to explain queuing upstream of a bottleneck.
freeflowpass The 'freeflowpass' function estimates the relative locations of two vehicles where one passes the other.

-- G --

gbm Estimate speed 'u' at time 't' using a geometric Brownian motion model.
gbmtheta Estimate 'theta' of a geometric Brownian motion model.
gbmx Estimate distance 'x' given a geometric Brownian motion model and time t.

-- H --

h0 Space headway 'h0' at time 't' = 0.
h1 Space headway 'h1' at time 't1', the time the following vehicle initiates deceleration.
h2 Space headway 'h2' at time 't2', the time the following vehicle driver sees the lead vehicle has decelerated.
h3 Space headway 'h3' at time 't3', the time the lead vehicle has decelerated to breakdown speed 'u0'.
hsafe Safe headway 'h' between lead and following vehicles. Speed 'u' of lead vehicle is measured in fps.

-- L --

L 'L' is a matrix containing information about the lead vehicle. The bottleneck is located at 'x = 0'.
lane 'lane' is a vector that designates the lane drivers are traveling in the 'brktrials' function.
lanedf 'lanedf' returns a vector of vehicles 'veh' in 'lane'.
leff 'leff' is the effective length of a vehicle.
lfmatrix The function 'lfmatrix' displays 'cflist', the lists 'L' and 'Fw' information for lead and following vehicles, respectively.
logisticmodel The function 'logisticmodel' estimates the parameters of logistic regression model using a binomial formula and logit link function for data 'QUKtdayX'.

-- M --

merge 'merge' produces 't-x' trajectories for a pair of lead and following vehicles.
merge3 'merge3' produces 't-x' trajectories for a pair of lead and following vehicles for 'brktrial3'.
mergedemo 'mergedemo' produces 't-x' trajectories for a pair of lead and following vehicles.

-- N --

nopass 'nopass' produces 't', 'u' and 'x' for lead and following vehicles downstream of a bottleneck

-- P --

passplot The function 'passplot' plots the data from 'brksummary', 'freeflowpass', 'decelmerge' data frames.
plotcrossover A 'ggplot2' plot of crossover traffic data.
plotdesire3 'plotdesire3' creates 't-x' desire-line trajectories.
plotfollow Produces a time-distance 't-x' trajectory for 'vehicle i = 2'.
plotfollow3 'plotfollow3' adds a new trajectory to an existing graph.
plotlead Produces a time-distance 't-x' trajectory for the lead vehicle, 'vehicle = 1'.
plotmerge3 'plotmerge3' creates 't-x' safe headway trajectories.
plotoptimize 'plotoptimise' produces 't-x' trajectories for 'nveh' drivers
plottux 'plottux' produces 't-u' and 't-x' trajectories for a lead and following vehicles on a ring road,
plotupstream 'plotupstream' produces 't-x' trajectories for lead and following vehicles at a bottleneck

-- Q --

QUKtdayX I-93 data set

-- R --

rrheadway 'rrheadway' is a function to estimate the traffic flow 'q' on a ring road.
rrheadwayu 'rrheadwayu' is a function used to find the speed 'u' on a ring road at 'x = 0'.
rrtrials 'rrtrials' produces 't-x' trajectories for lead and following vehicles on a ring road
run The 'run' function is a wrapper for the 'trial' and 'plotfollow3' functions.

-- S --

safecrossover The function 'safecrossover' a graph showing driver conflict of two vehicles changing lanes.
schematic The function 'schematic' defines key features of a simple bottleneck
speedboxplot The function 'speedboxplot' plots the data from a data frame 'QUKtdayX'
speedplot A scatter plot of traffic data.
speedts 'speedts' speed data used by 'speedtsplot'
speedtsplot The function 'speedtsplot' plots the data from the 'speedts' data frame.

-- T --

t0 't0' is the time the analysis is initiated.
t1 't1' is time the following vehicle realizes the lead vehicle is decelerating.
t2 't2' is time the following vehicle realizes the lead vehicle is decelerating.
t3 't3' is time the lead vehicle completes deceleration.
theta The exponential deceleration rate 'theta' of the lead vehicle.
trajectoryab 'trajectoryab' fits a second-order velocity model and produces a 't-x' trajectory for 'vehicle = i' where 'i = 3,4, ..., nveh'.
trajectoryab3 'trajectoryab3' fits a second-order velocity model and produces a 't-x' trajectory for 'vehicle = i' where 'i = 3,4, ..., nveh'.
trial The function 'trial' produces traffic performance information, stored in lists 'L' and 'Fw' for lead and following vehicles, respectively/ 'L' and 'Fw' contain the information needed to graph a time-distance 't-x' trajectories for two vehicles.
tuxvfix3 'tuxvfix3' fixes 'hsafe' violations for vehicle 'veh' in matrix 'tuxv'.

-- U --

uab Estimate distance 'u' using second-order speed function.
ubreakdown The 'ubreakdown' function generates a breakdown speed vector 'ubk' assuming a lognormal distribution.
uf0 The following 'f' vehicle speed 'uf0' at time 't0'.
uf1 The following 'f' vehicle speed 'uf1' at time 't1'.
uf2 The following 'f' vehicle speed 'uf2' at time 't2'.
uf3 The following 'f' vehicle speed 'uf3' at time 't0'.
uk_sdk A speed volatility model.
ul0 The lead 'l' vehicle speed 'ul0' at time 't0'.
ul1 The following 'l' vehicle speed 'ul1' at time 't1'.
ul2 The following 'l' vehicle speed 'ul2' at time 't2'.
ul3 The following 'l' vehicle speed 'ul3' at time 't3'.
usdBBridge The 'usdBBridge' function from Iacus.
usdzipper The 'usdzipper' function is used to perform a sensitivity analysis of a single vehicles in traffic breakdown.

-- V --

vehdf 'vehdf' selects information about vehicle 'veh' of the 'df' matrix for analysis with the 'brktrials2' function.
vehfix 'vehfix' fixes 'hsafe' violation with speed 'ufix' and location 'xfix' and 'yfix' vectors from 'brktrials2'
vehid 'vehid' selects information about vehicle 'veh' from the 'tuxv' matrix for analysis with the 'brktrials3' function.
vehtfix 'vehtfix' fixes 'hsafe' violations for vehicle 'veh'.

-- X --

xab Estimate distance 'x' using second-order speed function.
xabmerge 'xabmerge' produces 't-x' trajectories for a pair of lead and following vehicles.
xabmerge3 'xabmerge3' produces 't-x' trajectories for a pair of lead and following vehicles.
xabparam Estimate the parameters 'a' and 'b' of a first-order acceleration model 'a + b * t'.
xf0 The lead 'f' vehicle location 'xf0' at time 't0'.
xf1 The lead 'f' vehicle location 'xf1' at time 't1'.
xf2 The lead 'f' vehicle location 'xf2' at time 't2'.
xf3 The lead 'f' vehicle location 'xf3' at time 't3'.
xfollow Estimate 'x' distance traveled using a constant speed model.
xl0 The lead 'l' vehicle location 'xl0' at time 't0'.
xl1 The lead 'l' vehicle location 'xl1' at time 't1'.
xl2 The lead 'l' vehicle location 'xl2' at time 't2'.
xl3 The lead 'l' vehicle location 'xl3' at time 't3'.
xstart 'xstart' is a vector that designates the start 'x' location for the 'brktrials' function.

-- Z --

zipper The 'zipper' function can be used to simulate interaction among three vehicles in car following on a single lane or three vehicles merging on a two-lane highway.