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TO THE BLACK BOX AND BACK –
The TRANS Model
October 2008
2The TRANS Model
EXCLUSIVE
REVELATIONS
FROM CONCEPTORS OF
TOOL
THAT SEES INTO THE
FUTURE !Ottawa --
3
What does it model ? to replicate reality
The TRANS Model
ultimately: trips over the transportation networks
- persons - passenger vehicles
- bus - rail- auto
National Capital Region at present and under
any set of circumstancesin the future
4The TRANS Model
5
What is it all founded upon?
The TRANS Model
6
What are households made of ? Size : 1, 2, 3, 4, 5, 6+ persons
Age groups: 6 ranges
Number of workers : 0, 1, 2, 3+
Housing type: detached house vs. apartment
- # of non-workers with no worker (e.g. retirees, students)- # of non-workers with 1 worker (e.g. stay-at-home)
- # of non-workers with 2+ workers (e.g. children)
Household Composition
The TRANS Model
7
What influences a household’s mobility ? # of workers vs. # of cars
# of cars vs. housing type
# of non-workers vs. # of workers and # of cars
% of detached houses in neighbourhood % of low-income households in neighbourhood Population density in neighbourhood
Car Sufficiency
The TRANS Model
8
For what reasons do we make trips ?
Work : workplace, work-related
School : high school,18 or younger
University : university, college / CEGEP,other schools for 19+
Maintenance : shopping / banking, medical,pick up / drop off
Discretionary : leisure / sport, eating out,visiting relatives and friends
Travel Purpose
The TRANS Model
9
What makes households generate travel ? for work : # of workers
for maintenance : # of workers, # of non-workers,car sufficiency, % of detached houses,population density
discretionary : # of workers, # of non-workers,high car sufficiency, % of detached houses,density of retail+services in the area
for university and school : # of non-workers
What makes households not travel ? % of low-income in area, low car sufficiency
The TRANS Model
10
What makes a neighbourhood a destination ? for work : employment (# and density), population
for maintenance : retail, office, education and health employment, shopping gross leasable area, population, school enrollment
discretionary : retail and service employment, detached houses (over apartments),school enrollment
for university : enrollment, health employment for school : enrollment, population
The TRANS Model
11
3 levels of geography used, to take into account what happens in adjacent areas
The TRANS Model
- nearly 600 traffic zones …- … regrouped into 94 super-zones (clusters) …- … regrouped into 26 TRANS districts
What if an open field lies today where a newneighbourhood may take shape in the future?
e.g. population density, employment density, retail density
12
Walk / bicycle travel is considered explicitly for each travel purpose separately
The TRANS Model
for origins and destinations separately What drives walk / bicycle travel ?
car sufficiency (# of cars vs. # of workers in HH) age (< or > than 45) population / employment / retail density
at various levels of geography school / university enrollment % of low income households % of detached houses
13
The sequence of someone’s travel matters !
The TRANS Model
travel purpose going / coming back directly vs. stopping over purpose of stop-over location of stop-over
- geographically ( “on my way” )- with respect to start and end of one’s itinerary (element of familiarity)
14
i j1. Tours
i j2. Directional half-tours
i j
k
k
3. Chained trips
The TRANS Model
Breaking down someone’s travel :
15
15time of daycombosfor tours
5 times of day
for trips
The TRANS Model
Breaking Down Someone’s Travel (cont’d) :
Early Early
Early
Early Midday
Early
Early Late
Midday
Late
Midday Midday
Midday
Midday Late
Late
Late Late
Midday9:00-15:29
Late18:29-28:00
Early4:00-6:29
AM6:30-8:59
AM
AM AM
AM
AM
AM
outbound (→)
PM
PM
PM
PM PM
PM
PM15:30-18:29
focus on 9 relevant tour times of day, to convert into2 relevant trip times of day : AM and PM periods
inbound (←)
16
Choosing to travel at a given time of day is driven by :
The TRANS Model
varies depending on :
- level of car sufficiency- same variables seen earlier (population, employment, enrollment, density, etc.)
- travel purpose- outbound vs. inbound direction
- origin of travel- destination of travel
- travel duration (number of time periods spanned)
e.g. work trip from home in the AM, for the daymaintenance trip from work in the PM, for a short whilereturn home trip from maintenance in the evening
17
Mode
Autodriver
Transit
Autodriver
Autopassenger
Lo
t lo
ca
tio
nRail with walk/bus access &
egress
P&Rrail
K&Rrail
Bus withwalk access
& egress
P&Rbus
K&Rbus
Schoolbus
Lo
t lo
ca
tio
n
Lo
t lo
ca
tio
n
Lo
t lo
ca
tio
n
Autopassenger
Schoolbus
The TRANS Model
nestedlevelof modechoice
Choosing a mode (motorized modes)
Limited substitution driver / passenger
school trips only
Not enough data for separate bus / rail access sub-nests
Strong substitution of transit modes
18
Choosing a mode (cont’d)
The TRANS Model
two sub-models : one for AM, one for PM for each travel purpose separately driven by :
- level of car sufficiency- same variables seen earlier (population, employment, enrollment, density, etc.)- free flow auto time - auto (e.g. toll) + parking cost- transit in-vehicle time - fare + auto access cost- # of boardings - walk time + weight
- wait time + weight- transfer penalty
Different for different travel purposes
19
Choosing a mode (cont’d)
The TRANS Model
also driven by less standard variables :- auto delay coefficient
The difference in actual auto time vs. free flow time revealing the importance (statistically significant) attributed to reliability
- Transitway reliability bonusThe proportion of the in-vehicledistance of a transit triptravelled on the Transitway / O-Trainas a strong positive factorin favour of transit
Higher values for some work and discretionary trips
20
Choosing a mode (cont’d)
The TRANS Model
rail path ratio coefficient
modal transfer conservatismTransit improvements would attractfewer auto users compared to transit users attracted by highway improvements
Introduced to control the simulatedchoice of rail for very short portionsof longer-distance trips
21The TRANS Model
Trips are then assigned to the networks
School bus
X
P+R bus
Walk to bus
Auto passenger
Auto driver
Transit networkAuto networkTrips by mode
X
K+R bus
P+R rail
Walk to rail
K+R rail
X
X (bus leg)
X (bus leg)
X (auto leg)
X (auto leg) X (rail leg)
X (rail leg)
22
What do the networks look like ?
The TRANS Model
represented by 8,000 nodes and 23,000 links
- freeways, highways, arterials, collectors
- some local streets- ramps, interchanges- Transitway, reserved bus lanes, O-Train- Transitway stations (local, express platforms)
AM and PM
23
Which way do auto trips take ?
auto travel time as a function of
The TRANS Model
- traffic volume - # of lanes- posted speed limit - capacity- roadway type and level of interference
location (urban, suburban, rural)access to / from adjacent lotscontrol at intersections
function (highway, arterial, collector, etc.)
etc.
24
Which routes do transit passenger trips take ?
transit passenger trips subject to
The TRANS Model
- transit travel time
As a function of auto travel time or scheduleor posted speed limit (on exclusive facilities)
- frequency of service
fare structure (local, express, rural,including outbound and homebound rules)
- stopping patterns
- boarding / transferring inconvenience
25
And then what ?
time lost in traffic congestion
The TRANS Model
distances travelled overall speed etc.
traffic volumes on individual links transit passenger volumes on individual links,
on individual routes
. . .
Alternative AAlternative B
Alternative C
Alternative D
Alternative E
Alternative F
26
Is the model finished ?
Other time periods of the day could be added …
The TRANS Model
… perhaps toward full day simulations
peak spreading(time-of-day sensitivity to congestion)
transition to micro-simulation andactivity-based structure