Inputs to the ARC ABM are stored in the following folders: INPUTS, PARAMETERS, WarmStart, and ctrampModels. The INPUTS and PARAMETERS folders are required for the model to function and contain a number of files. The WarmStart is only required if the warm start option is selected; however, it is the recommended approach to ensure more efficient model closure within the feedback loop routine. The model script must be run from within the root folder as the paths are relative. The INPUTS folder contains files that typically vary by model scenario while the PARAMETERS folder contains files that should not be changed. The ctrampModels folder stores all CT-RAMP Utility Expression Calculator (UEC) files and choice model alternatives files.

Section 6.1 Input Files

Within each of the required folders, there are expected files that are read by the model script. Any file missing from these folders will cause the model to fail in application. Table 6-1 includes the names and description of files required in the INPUTS folder. Some, if not all, of these files will vary between model scenarios. However, the file naming structure must remain the same. Table 6-2 provides the list of files required in the PARAMETERS folder. Except under special circumstances (e.g. splitting zones), these files should not be altered.

Table 6-1 INPUTS Folder Required Files

File Description
ARC_20{year}.GDB Cube geodatabase (highway and transit networks)
HSH{year}.CSV households stratified by income and size
EMP{year}.CSV population and employment by type
UNIV{year}.CSV university enrollment / zonal acres
PERSONS.CSV PopSyn person output
HOUSEHOLDS.CSV PopSyn household output
SchoolEnroll{year}.CSV K-12 school enrollment
ExtraZoneData{year}.PRN zone data file (parking information, CBD, etc.)
TOLLS{year].DBF toll rates by toll ID

Table 6-2 PARAMETERS Folder Required Files

File Description
ShadowPricing_1_0_Yr{year}.CSV Shadow pricing file (specific to model year)
CAPACITY.DBF hourly capacity lookup
AUXLANE.DBF hourly capacity for auxiliary lanes
FFSPEED.DBF free-flow speed lookup
AMSPEED.DBF AM peak period speed lookup (first feedback loop)
ExternalCounties.DBF external county population data
Externals.DBF external station data (counts, % truck, etc.)
TruckZones.DBF truck zone flag for commercial model
IntermodalZones.DBF TAZs with intermodal yards
I285_ZONES.DBF I-285 zone flag for truck trips inside I-285
ENPLANEMENTS.DBF annual enplanement forecasts for Hartsfield-Jackson
IEPCSTA.DAT interstate flag for external stations
IE_FrictionFractors.PRN I-E passenger car friction factors
NWTAZ10G.PRN 2010 population / employment data
EEPC00.VTT year 2000 E-E passenger car trip table
EETRK05.VTT year 2005 E-E truck trip table
FFactors.PRN I-I and I-E truck friction factors
DeltaAM.TRP delta truck trip matrix for AM
DeltaMD.TRP delta truck trip matrix for MD
DeltaPM.TRP delta truck trip matrix for PM
DeltaNT.TRP delta truck trip matrix for NT
Transit_Walk.FAC transit path parameters for walk access/egress
Transit_KNR.FAC transit path parameters for KNR access / walk egress
Transit_KNR_INBOUND.FAC transit path parameters for walk access / KNR egress
Transit_PNR.FAC transit path parameters for PNR access / walk egress
Transit_PNR_OP.FAC transit path parameters for walk access / PNR egress
Transit_System.DAT transit system data file (modes, operators, etc.)
Transit_Fares.FAR transit fare structures

Section 6.2 Traffic Analysis Zones

The model area was expanded to include Dalton County which resulted in more internal TAZs. There are now 5,922 internal zones within the ARC boundary. The zones were built from Census 2010 block geographies and are nested within Census tracts. Table 6-3 provides the zone numbering by county and a graphic of the zone boundaries is illustrated by Figure 6-1.

Table 6-3 Zone Ranges by County

County FIPS Code Zone Range
Fulton 13121 1-1296
DeKalb 13089 1297-1943
Cobb 13067 1944-2508
Gwinnett 13135 2509-3006
Rockdale 13247 3007-3141
Henry 13151 3142-3386
Clayton 13063 3387-3624
Fayette 13113 3625-3830
Douglas 13097 3831-3988
Cherokee 13057 3989-4209
Coweta 13077 4210-4437
Forsyth 13117 4438-4631
Paulding 13223 4632-4771
Bartow 13015 4772-4942
Carroll 13045 4943-5119
Spalding 13255 5120-5263
Newton 13217 5264-5407
Walton 13297 5408-5530
Barrow 13013 5531-5635
Hall 13139 5636-5873
Dawson 13085 5874-5922
Figure 6-1. Traffic Analysis Zones

Figure 6-1. Traffic Analysis Zones

Section 6.3 Highway Networks

This section details the attributes in the highway networks, speeds, capacities and how to treat reversible lanes and toll facilities.

Section 6.3.1 Network Attributes

The network attributes necessary for the model to function properly are provided in Table 6-4. These attributes include items such as the number of lanes, facility type, distance, etc. The attributes in Table 18 are also recommended when coding networks to facilitate summarizing the output networks. Special attention should be given to the traffic count locations especially when copying/pasting link attributes or splitting existing links as it could result in traffic counts in incorrect locations.

Table 6-4 Highway Network Attributes

Variable Description
A / B Beginning node / ending node
DISTANCE Link distance (miles)
PROHIBITION 0 = No Restrictions
1 = Trucks Prohibited
2 = HOV 2+
3 = SOV toll – HOV 2+ free – no trucks
4 = Truck Only
5 = I-285 Bypass
6 = HOV 3+
7 = SOV and HOV 2 toll; HOV 3+ free; no trucks
8 = SOV and truck toll; HOV 2+ free
9 = SOV, HOV 2, and truck toll; HOV 3+ free
10 = Truck only toll
11 = HOV 2 toll; HOV 3+ free; No trucks or SOV
12 = SOV and HOV 2+ toll; no trucks
13 = All vehicles allowed and tolled
LANES Number of through lanes in one direction (including the number of auxiliary lanes)
AUXLANE Number of auxiliary lanes
TOLLID Toll identifier
LANESEA Number of lanes in EA period (if > 0, replaces lanes)
LANESAM Number of lanes in AM period (if > 0, replaces lanes)
LANESMD Number of lanes in MD period (if > 0, replaces lanes)
LANESPM Number of lanes in PM period (if > 0, replaces lanes)
LANESEV Number of lanes in EV period (if > 0, replaces lanes)
FACTYPE 0 = Centroid Connectors
1 = Interstate / Freeway
2 = Expressway
3 = Parkway
4 = Freeway HOV Buffer Separated
5 = Freeway HOV Barrier Separated
6 = Freeway truck only
7 = System to system ramp
8 = Exit ramp
9 = Entrance Ramp
10 = Principal arterial
11 = Minor arterial
12 = Arterial HOV
13 = Arterial truck only
14 = Collector
50 = Transit Only Link: Neighborhood Local
51 = Transit Only Link: Local Roads and Collectors
52 = Transit Only Link: Park-n-ride lot connector
53 = Transit Only Link: Transfer links between rail and bus
54 = Associated with BRT Routes (Future year coding)
98 = Connections to Transit Stations (pedestrian bridges, direct walk ups, etc)
99 = MARTA Heavy Rail Line
TRNDIST Fixed guideway transit distance (miles)
TRNSPD Fixed guideway transit speed (MPH)
TRNTIME Fixed guideway transit time (minutes)
HOVMERGE Flag for HOV/HOT lane merge links (0 or 1 with 1 indicating the link is a merge link)
RAMPFLAG Flag for loop ramps (0 or 1 with 1 indicating a loop ramp)
WEAVEFLAG Flag for approaches to major freeway to freeway interchanges (0 or 1 with 1 indicating link is a major weave link)

Table 6-5 Recommended Highway Network Attributes

Variable Description
NAME Facility name
COUNTY Barrow = 13
Bartow = 15
Carroll = 45
Cherokee = 57
Clayton = 63
Cobb = 67
Coweta = 77
Dawson = 85
DeKalb = 89
Douglas = 97
Fayette = 113
Forsyth = 117
Fulton = 121
Gwinnett = 135
Hall = 139
Henry = 151
Newton = 217
Paulding = 223
Rockdale = 247
Spalding = 255
Walton = 297
FCLASS 1 = Interstate
2 = Other Freeways & Expressways
3 = Other Principal Arterial
4 = Minor Arterial
5 = Major Collector
6 = Minor Collector
7 = Local
CNTSTATION GDOT traffic count station identifier
DIRAADT00 Directional average annual daily traffic by year
DIRAADT05 Directional average annual daily traffic by year
DIRAADT08 Directional average annual daily traffic by year
DIRAADT10 Directional average annual daily traffic by year
DIRAADT15 Directional average annual daily traffic by year
DIRAWDT00 Directional average weekday traffic by year
DIRAWDT05 Directional average weekday traffic by year
DIRAWDT08 Directional average weekday traffic by year
DIRAWDT10 Directional average weekday traffic by year
DIRAWDT15 Directional average weekday traffic by year
SCREENLINE Screen-line number for base year validation
ATR flag indicating GDOT permanent count station
ATR_DIR directionality of count
HR1 to HR24 2010 hourly volume (ATR locations)
CNTFAC flag indicating HOV/GP count factoring
FACTOR factor applied to split counts between HOV / GP
GPID Corridor identifier for toll optimization
EASPD Observed NPMRDS travel speeds for EA period
AMSPD Observed NPMRDS travel speeds for AM period
MDSPD Observed NPMRDS travel speeds for MD period
PMSPD Observed NPMRDS travel speeds for PM period
EVSPD Observed NPMRDS travel speeds for EV period

Section 6.3.2 Capacities

In previous model versions, the lookups for link capacities were embedded in the model script. In this newer version, the lookup has been transferred to a DBF structure which is called within the code. The table is called CAPACITY.DBF and is located in the PARAMETERS folder. Table 6-6 shows the hourly capacities by facility type and area type. Similarly, the capacity for the auxiliary lanes is called AUXLANE.DBF (Table 6-7) and is also located in the PARAMETERS folder.

Table 6-6 Hourly Capacities

NAME FACTYPE ATYPE 1 ATYPE 2 ATYPE 3 ATYPE 4 ATYPE 5 ATYPE 6 ATYPE 7
centroid connector 0 10000 10000 10000 10000 10000 10000 10000
interstate/freeway 1 1900 1900 2000 2000 2050 2100 2100
expressway 2 1200 1200 1300 1350 1400 1450 1450
parkway 3 1150 1150 1250 1300 1350 1400 1400
freeway HOV (concurrent) 4 1900 1900 2000 2000 2050 2100 2100
freeway HOV (barrier sep) 5 1900 1900 2000 2000 2050 2100 2100
freeway truck only 6 1900 1900 2000 2000 2050 2100 2100
system to system ramp 7 1300 1400 1500 1600 1700 1700 1700
exit ramp 8 800 850 850 850 850 900 900
entrance ramp 9 900 900 950 950 1000 1050 1100
principal arterial 10 1000 1050 1100 1150 1200 1250 1300
minor arterial 11 900 900 950 1000 1000 1050 1100
arterial HOV 12 1000 1050 1100 1150 1200 1250 1300
arterial truck only 13 900 900 950 1000 1000 1050 1100
collector 14 750 800 800 850 850 900 900

Note: ATYPE1-CBD; ATYPE2-Urban Commercial; ATYPE3-Urban Residential; ATYPE4-Suburban Commercial; ATYPE5-Suburban Residential; ATYPE6-Exurban; ATYPE7-Rural

Table 6-7 Auxiliary Lane Capacities

NAME FACTYPE AUXCAP
centroid connector 0 0
interstate/freeway 1 1200
expressway 2 900
parkway 3 600
freeway HOV (concurrent) 4 900
freeway HOV (barrier sep) 5 900
freeway truck only 6 900
system to system ramp 7 900
exit ramp 8 0
entrance ramp 9 0
principal arterial 10 300
minor arterial 11 300
arterial HOV 12 300
arterial truck only 13 300
collector 14 300

Section 6.3.3 Speeds

Similar to the capacities, link speeds were also previously embedded in the model script. These have also been converted to a DBF structure residing in the PARAMETERS folder. Table 6-8 provides the free-flow speeds by facility type and area type while Table 6-9 depicts the AM congested speeds for the first feedback loop.

Table 6-8 Free-Flow Speeds

NAME FACTYPE ATYPE1 ATYPE2 ATYPE3 ATYPE4 ATYPE5 ATYPE6 ATYPE7
centroid connector 0 7 11 11 11 11 14 14
interstate/freeway 1 62 63 63 63 64 65 66
expressway 2 43 46 49 52 55 58 61
parkway 3 43 46 49 52 55 58 61
freeway HOV (concurrent) 4 64 65 65 65 66 67 68
freeway HOV (barrier sep) 5 64 65 65 65 66 67 68
freeway truck only 6 62 63 63 63 64 65 66
system to system ramp 7 50 50 50 55 55 55 55
exit ramp 8 50 50 50 50 50 50 50
entrance ramp 9 50 50 50 50 50 50 50
principal arterial 10 23 26 31 35 41 48 53
minor arterial 11 21 26 29 33 38 43 48
arterial HOV 12 21 26 29 33 38 43 48
arterial truck only 13 21 26 29 33 38 43 48
collector 14 17 23 24 26 30 35 45
Transit Only: Neighborhood Local 50 12 12 12 12 12 12 12
Transit Only: Locals and Collectors 51 20 20 20 20 20 20 20
Transit Only: PNR lot connector 52 20 20 20 20 20 20 20
Transit Only: Transfer between rail and bus 53 20 20 20 20 20 20 20

Note: ATYPE1-CBD; ATYPE2-Urban Commercial; ATYPE3-Urban Residential; ATYPE4-Suburban Commercial; ATYPE5-Suburban Residential; ATYPE6-Exurban; ATYPE7-Rural

Table 6-9 AM Congested Speeds - First Feedback Loop

NAME FACTYPE ATYPE1 ATYPE2 ATYPE3 ATYPE4 ATYPE5 ATYPE6 ATYPE7
centroid connector 0 7 11 11 11 11 14 14
interstate/freeway 1 37 38 47 51 55 60 68
expressway 2 38 40 42 42 44 49 52
parkway 3 28 30 41 40 46 48 49
freeway HOV (concurrent) 4 50 54 60 65 64 70 70
freeway HOV (barrier sep) 5 50 54 60 65 64 70 70
freeway truck only 6 50 54 60 65 64 70 70
system to system ramp 7 33 33 34 43 46 48 55
exit ramp 8 12 15 19 22 22 25 30
entrance ramp 9 25 25 30 30 30 35 35
principal arterial 10 24 25 27 30 34 41 43
minor arterial 11 22 23 27 28 31 36 40
arterial HOV 12 22 23 27 28 31 36 40
arterial truck only 13 22 23 27 28 31 36 40
collector 14 22 22 26 27 29 36 39
Transit Only: Neighborhood Local 50 12 12 12 12 12 12 12
Transit Only: Locals and Collectors 51 20 20 20 20 20 20 20
Transit Only: PNR lot connector 52 20 20 20 20 20 20 20
Transit Only: Transfer between rail and bus 53 20 20 20 20 20 20 20

Note: ATYPE1-CBD; ATYPE2-Urban Commercial; ATYPE3-Urban Residential; ATYPE4-Suburban Commercial; ATYPE5-Suburban Residential; ATYPE6-Exurban; ATYPE7-Rural

Section 6.3.4 Lane Coding

When coding the number of lanes, there are certain guidelines to follow for auxiliary lanes and when the facility may operate with a different number of lanes by time period. The LANES field should include auxiliary lanes. There are several attributes in the network that allow for varying the number of lanes by time period:

  • LANESEA: available lanes during early AM period (3:00 AM to 6:00 AM)
  • LANESAM: available lanes during AM Period (6:00 AM to 10:00 AM)
  • LANESMD: available lanes during midday Period (10:00 AM to 3:00 PM)
  • LANESPM: available lanes during PM Period (3:00 PM to 7:00 PM)
  • LANESEV: available lanes during evening/late night Period (7:00 PM to 3:00 AM)

If the lanes do not vary by time period, the LANES attribute should be the only lanes attribute coded (i.e. the period lanes should all be set to zero). However, if the lanes do vary by period, then the appropriate values should be entered by time period. The code is written such that if the period lanes are zero, the program defaults to LANES when computing capacity. If the period lanes are greater than zero, the program uses the period lanes to compute capacity. Some examples are provided below in Table 6-10 through Table 6-12. In example 1, four lanes (two lanes each direction) are available throughout the day which requires only LANES to be coded. The period lanes are left as zero.

Table 6-10 Time of Day Lanes Example 1

Attribute AB Direction BA Direction
LANES 2 2
LANESEA 0 0
LANESAM 0 0
LANESMD 0 0
LANESPM 0 0
LANESEV 0 0

Example 2 shows how one type of reversible lane could be handled. An additional lane is coded in the AB direction for the AM period; however, the BA direction for AM lanes is set to zero. For the AM period, this facility would operate as 3 lanes in the AB direction and 2 lanes in the BA direction (because LANES = 2). The reverse is true in the PM period (BA direction = 3 lanes, AB direction = 2 lanes). With no values coded in the EA, MD, and EV periods, the lanes would default to 2 lanes in each direction.

Table 6-11 Time of Day Lanes Example 2

Attribute AB Direction BA Direction
LANES 2 2
LANESEA 0 0
LANESAM 3 0
LANESMD 0 0
LANESPM 0 3
LANESEV 0 0

Example 3 shows a case where a one-way facility has lanes that are only available in the EA and AM period. In this example, only the LANES EA and LANESAM should have values. All other lane attributes should be coded as 0 (including LANES).

Table 6-12 Time of Day Lanes Example 3

Attribute AB Direction
LANES 0
LANESEA 2
LANESAM 2
LANESMD 0
LANESPM 0
LANESEV 0

Section 6.3.5 Toll Facilities

The coding of toll facilities has not changed in the new model version. The user must code the TOLLID attribute on the appropriate links to represent a toll facility. The value on this attribute is at the user’s discretion; however, it is recommended that the user follow a defined set of guidelines when coding. One method is to make the first digit of the toll identifier unique to the corridor it represents and the second digit a directional flag. An example is provided below in Figure 6-2. Discussed later in this document is the process of optimizing tolls for managed lane facilities. To optimize tolls, a comparison between the travel times of the general-purpose lanes and managed lanes is necessary. To accommodate this, a link attribute called GPID can be used to inform the toll optimization algorithm of the level-of-service characteristics of the competing lanes. The GPID should be coded with the same number as the competing managed lane facility (i.e. TOLLID = 11 and GPID = 11 for a competing route). Further information is provided in the highway network coding portion of this document.

Figure 6-2. Toll ID Example

Figure 6-2. Toll ID Example

The toll rates are defined by the file TOLLS{year}.DBF residing in the INPUTS folder. The {year} should be representative of the last two digits of the model run year. Within the file, there should be six column attributes labeled as follows:

  • TOLLID: identifier used to provide the linkage to the highway network
  • TOLLEA: toll rate for early AM
  • TOLLAM: toll rate for AM period
  • TOLLMD: toll rate for midday period
  • TOLLPM: toll rate for PM period
  • TOLLNT: toll rate for evening/late night period
  • FIXED: flag which informs the model if the toll is fixed or distance based

The TOLLID in the database should correspond to the toll identifier coded in the highway network. Within the model this identifier is used as a lookup value to determine the toll rates to be assessed on the highway links. The toll rate should be entered in cents (e.g. one dollar is 100) and applied to the appropriate time period. If the toll rate is unchanged throughout the day, each period should have the same value.

The FIXED attribute is a simple Boolean logic applying a ‘1’ or ‘0’ which informs the program how to treat the toll (‘1’ is true and ‘0’ is false). If the toll rate is fixed, the value should be set to ‘1’. If the toll rate is a distance based toll, the FIXED attribute should be set to ‘0’ which tells the program to compute the toll based on the rate and link distance. The entered toll values should be reflective of the rates applied per mile for each time period. An example toll file setup is provided below in Table 6-13.

Table 6-13 Toll ID Database

TOLLID TOLLEA TOLLAM TOLLMD TOLLPM TOLLEV FIXED
21 5 20 5 10 5 0
22 5 10 5 20 5 0
51 5 25 5 10 5 0
52 5 10 5 25 10 0

Section 6.3.6 Prohibitions

The ARC model includes the ability to test various lane restrictions (e.g. HOT lanes, truck lanes, etc.). This is handled through coding a link attribute in the network called PROHIBIT. The path building procedures in the model script utilize this link attribute to determine what vehicle types can use the links. Figure 6-3 provides a list of the prohibition codes and how each vehicle type is treated.

Figure 6-3. Prohibition Coding

Figure 6-3. Prohibition Coding

Section 6.4 Transit Networks/System

This section provides information regarding the associated transit input files.

Section 6.4.1 Transit Route Files

The transit route files are similar to the previous model versions but are now stored in the Cube geodatabase. There are two transit networks stored in the geodatabase:

  • NONPREMIUM_TRN{year}: All non-premium transit routes
  • PREMIUM_TRN{year}: Premium only transit routes

The route files can still be viewed in a text format containing line information and node numbers. The primary differences in the route files are some attribute name changes, required variables, and PT specific available attributes. More information is provided about the route files in the transit coding section of this document.

Section 6.4.2 Transit System Data File

The transit modes, first and second wait curves, and operators are defined in the transit system data file called TRANSIT_SYSTEM.DAT located in the PARAMETERS folder. This file contains mode numbers and names as provided in Figure 6-4. The wait curves are stored in this file with an example shown in Figure 6-5. Also, the operator numbers are stored here as well. The operator numbers are set so that if an operator has varying fares by mode, each mode would have a unique operator. For example, if an operator charged $2.00 for local bus usage but $3.00 for rail, there would be an operator number for both local bus and rail. Figure 6-6 shows an example of how the operators are specified.

Figure 6-4. System Data File Example Modes

Figure 6-4. System Data File Example Modes

Figure 6-5. System Data File Example Wait Curves

Figure 6-5. System Data File Example Wait Curves

Figure 6-6. System Data File Example Operators

Figure 6-6. System Data File Example Operators

Section 6.4.3 Transit Factor Files

The transit factor files are in text format and contain information regarding the access/egress modes, path building parameters, and linkage between the fare systems and operators. The wait curves specified in the transit system data file are also linked here for the initial wait time and transfer wait time. There are six transit factor files located in the PARAMETERS folder:

  • TRANSIT_WALK.FAC: walk access factors
  • TRANSIT_KNR.FAC: KNR access factors (KNR access mode)
  • TRANSIT_KNR_INBOUND.FAC: KNR access factors (KNR egress mode)
  • TRANSIT_PNR.FAC: PNR access factors (PNR access mode)
  • TRANSIT_PNR_INBOUND.FAC: PNR access factors (PNR egress mode)

An example of the format of the factor files is provided in Figure 6-7.

Figure 6-7. Transit Factor File Walk Access Example

Figure 6-7. Transit Factor File Walk Access Example

Section 6.4.4 Transit Fare File

The transit fare structures are also specified in a text file located in the PARAMETERS folder and is titled TRANSIT_FARES.FAR. An example format is shown in Figure 6-8. This file specifies the fare amount as well as the how the fare is assessed for each of the fare systems defined in the transit factor files. Linking the fare systems between the two files is handled by the test: FARESYTEM, NUMBER=# where the number is equal to the fare system. The fare systems also include names (e.g. MARTA FARES) to make interpretation easier. The way in which the fares are implemented for a given fare system are handled by STRUCTURE. There is much more flexibility in PT for how the fares are assessed. For example, fares can be applied as a single boarding fare, distance based, or from fare zone to fare zone. IBOARDFARE is the boarding fare for the system and is entered in dollars. To define how the fares are treated between fare systems, the FAREFROMFS is used. The FAREROMFS is specified from each of the fare systems to the system that is being defined. The value entered represents the fare incurred when transferring from another fare system to the current fare system. For example, if all operators allow for free transfers between systems, then the FAREFROMFS would all be set to zero. However, if fare system 1 charges a $1.00 and fare system 2 charges $2.00, there could be an up-charge from fare system to 1 to fare system 2 of $1.00. This would be specified using the FAREFROMFS.

An example of free transfers versus two different up charge scenarios is illustrated below:

Figure 6-8. Transit Fare Charge Example

Figure 6-8. Transit Fare Charge Example

Figure 6-9. Transit Factor File Walk Access Example

Figure 6-9. Transit Factor File Walk Access Example

Figure 6-10. Fare Structure Cube Help

Figure 6-10. Fare Structure Cube Help

Section 6.5 Socioeconomic Data Files

The input socioeconomic (SE) files have been modified and are now stored in CSV files located within the INPUTS folder. Employment by category and population is stored in EMP{year}.CSV with the format shown in Table 6-14. The household file (HSH{year}.CSV) is split by income group and household size using the format in Table 6-15. The university enrollment and acres are now stored in a separate file called UNIV{year}.CSV with the format provided in Table 6-16. Grade school enrollment is also in Table 6-17.

Table 6-14 Population and Employment Input

Column Name Description
1 TAZ Zone
2 FIPS County FIPS
3 EMP Total employment
4 N11 NAICS - agriculture, forestry, fishing, and hunting
5 N21 NAICS - mining, quarrying, and oil and gas extraction
6 N22 NAICS - utilities
7 N23 NAICS - construction
8 N313233 NAICS - textile miles /
9 N42 NAICS - wholesale trade
10 N4445 NAICS - retail trade
11 N4849 NAICS - transportation and warehousing
12 N51 NAICS - information
13 N52 NAICS - finance and insurance
14 N53 NAICS - real estate and rental and leasing
15 N54 NAICS - professional, scientific, and technical services
16 N55 NAICS - management of companies and enterprises
17 N56 NAICS - administrative and support and waste management and remediation services
18 N61 NAICS - educational services
19 N62 NAICS - health care and social assistance
20 N71 NAICS - arts, entertainment, and recreation
21 N72 NAICS - accommodation and food services
22 N81 NAICS - other services (except public administration)
23 N92 NAICS - public administration
24 Cons SIC - construction
25 Manu SIC - manufacturing
26 TCU SIC - transportation, communication, utilities
27 Whol SIC - wholesale
28 Retail SIC - retail
29 FIRE SIC - financial, insurance, real estate
30 Serv SIC - service
31 Govt SIC - government

Table 6-15 Household Size by Income Group Input

Column Name Description
1 TAZ Zone
2 I1H1 Income Group 1; Size 1
3 I2H1 Income Group 2; Size 1
4 I3H1 Income Group 3; Size 1
5 I4H1 Income Group 4; Size 1
6 I1H2 Income Group 1; Size 2
7 I2H2 Income Group 2; Size 2
8 I3H2 Income Group 3; Size 2
9 I4H2 Income Group 4; Size 2
10 I1H3 Income Group 1; Size 3
11 I2H3 Income Group 2; Size 3
12 I3H3 Income Group 3; Size 3
13 I4H3 Income Group 4; Size 3
14 I1H4 Income Group 1; Size 4
15 I2H4 Income Group 2; Size 4
16 I3H4 Income Group 3; Size 4
17 I4H4 Income Group 4; Size 4
18 I1H5 Income Group 1; Size 5
19 I2H5 Income Group 2; Size 5
20 I3H5 Income Group 3; Size 5
21 I4H5 Income Group 4; Size 5
22 I1H6 Income Group 1; Size 6+

Table 6-16 University Enrollment

Column Name Description
1 TAZ Zone
2 UNIV Enrollment
3 ACRES Acres

Table 6-17 School Enrollment

Column Name Description
1 Zone Zone
2 EnrollDS Driving age enrollment
3 EnrollPD Pre-driving age enrollment

Section 6.6 Air Passenger Model

This section describes the input file required for running the air passenger model. The file is called ENPLANEMENTS.DBF and is located in the PARAMETERS folder. It contains the annual enplanements for several model years which are used in the model for the generation of air passenger trips. For intermediate years, the model interpolates between the two nearest years. The format of the file is shown in Table 6-18.

Table 6-18 Enplanements File

Column Name Description
1 Year Forecast year
2 Enplane Annual enplanements

Section 6.7 Externals

This section describes the input files required for the external models. There are seven files located in the PARAMETERS folder which are used for forecasting the external station volumes. The file formats are provided in Table 6-19 through Table 6-24. The file names and descriptions are:

  • EXTERNALS.DBF: Base year external station data (e.g. station number, road name, lanes, traffic counts, percent IE, percent EE, etc.)
  • EXTERNALCOUNTIES.DBF: Population forecasts for counties surrounding ARC model boundary
  • IEPCSTA.DAT: Text file classifying stations as interstate and non-interstate
  • IEPCFF.NEW: External station passenger car friction factors for work/non-work and interstate/non-interstate
  • EEPC15.VTT: External to external (EE) passenger car matrix used for frataring future year EE passenger car trips
  • EETRK05.VTT: EE truck trip tables for frataring future year EE truck trips
  • NWTAZ15G.PRN: Year 2015 base year SE data file for determining population/employment growth

Table 6-19 External Stations File

Column Name Description
1 N Station number
2 Name Road name
3 FIPS County FIPS code
4 EXTCNTSTA GDOT count station
5 LANES Number of lanes
6 EXTFLAG External station group ID
7 INTFLAG Interstate flag (0 = non-interstate, 1 = interstate)
8 AADT2000 Year 2000 Average Annual Daily Traffic
9 AADT2005 Year 2005 Average Annual Daily Traffic
10 AADT2010 Year 2010 Average Annual Daily Traffic
11 AADT2015 Year 2015 Average Annual Daily Traffic
12 AWDT2000 Year 2000 Average Weekday Traffic
13 AWDT2005 Year 2005 Average Weekday Traffic
14 AWDT2010 Year 2010 Average Weekday Traffic
15 AWDT2015 Year 2015 Average Weekday Traffic
16 PCINTWK % IE Passenger car interstate work
17 PCINTNW % IE Passenger car interstate non-work
18 PCNINTW % IE Passenger car non-interstate work
19 PCNINTN % IE Passenger car non-interstate non-work
20 CAREE % EE Passenger car
21 COMIE % IE Commercial vehicle
22 COMEE % EE Commercial vehicle
23 MTKIE % IE Medium duty truck
24 MTKEE % EE Medium duty truck
25 HTKIE % IE Heavy duty truck
26 HTKEE % EE Heavy duty truck

Table 6-20 External Counties File

Column Name Description
1 N External county number
2 COUNTY County name
3 POP00 Year 2000 county population
4 POP05 Year 2005 county population
5 POP10 Year 2010 county population
6 POP15 Year 2015 county population
7 POP20 Year 2020 county population
8 POP25 Year 2025 county population
9 POP30 Year 2030 county population
10 POP40 Year 2040 county population
11 POP50 Year 2050 county population

Table 6-21 External Station Interstate Flag File

Column Description
1 Station node
2 Interstate flag (I = interstate, N = non-interstate)

Table 6-22 External Station Passenger Car Friction Factors

Column Description
1 Travel Time
2 Friction factors for interstate work trips
3 Friction factors for interstate non-work trips
4 Friction factors for non-interstate work trips
5 Friction factors for non-interstate non-work trips

Table 6-23 External-External Passenger Car File

Table Name Description
1 EEPC EE Passenger Cars

Table 6-24 External-External Truck File

Table Name Description
1 COMEE EE Commercial vehicle
2 MTKEE EE Medium truck
3 HTKEE EE Heavy truck

Section 6.8 Commercial Vehicle and Truck Model

This section describes the input files required for the commercial vehicle, medium duty truck, and heavy duty truck models. There are three files located in the PARAMETERS folder which are used for forecasting truck trips in the region. These include a truck zone flag, the intermodal yards, and the friction factors for distribution. File formats are provided in Table 6-25 through Table 6-27 and are described below:

  • TruckZones.DBF: Zonal file flagging zones with higher than normal truck activity
  • IntermodalZones.DBF: Zonal file flagging intermodal zones and annual lifts
  • FFactors.PRN: Friction factors for I-I and I-E trips by truck type

Table 6-25 Truck Zone Flag File

Column Name Description
1 Zone Zone number
2 Flag Truck zone flag (1 = truck zone, 0 = non-truck zone)

Table 6-26 Intermodal Zone File

Column Name Description
1 TAZ Zone number
2 Name Name of intermodal yard
3 Annual Annual lifts
4 Type Flag for trip generation rate equation (1 or 2)

Table 6-27 Truck Model Friction Factors

Column Name
1 Time
2 Commercial vehicle I-I friction factors
3 Medium duty truck I-I friction factors
4 Heavy duty truck I-I friction factors
5 Commercial vehicle I-E friction factors
6 Medium duty truck I-E friction factors
7 Heavy duty truck I-E friction factors

Section 6.9 CT-RAMP Input Files

The CT-RAMP input files are located in the ctrampModels folder. The files are summarized in Table 6-28. Many of the UEC files, such as the Destination Choice UEC, contain multiple models. In addition, the complete definition of one destination choice model is actually spread across multiple files: DestinationChoice.xls, DestinationChoiceAlternatives.csv, DestinationChoiceAlternativeSample.xls, and DestinationChoiceSizeCoefficients.csv.

Table 6-28 CT-RAMP Model Input Files

File Name Description
Accessibility_utility.xls Accessibility calculation UEC
Accessibility_utility_constants.xls Additional constants for accessibility calculation
AtWorkSubtourFrequency.xls At work subtour frequency model UEC
AutoOwnership.xls Auto ownership model UEC
cbd_parking_zones.csv CBD parking zone alternatives
CoordinatedDailyActivityPattern.xls Coordinated daily activity pattern model UEC
DestinationChoice.xls Destination choice model UECs (mandatory, maintenance, discretionary, at work subtour)
DestinationChoiceAlternatives.csv Destination choice models alternatives (including walk market segments)
DestinationChoiceAlternativeSample.xls Destination choice model sample of alternatives UECs
DestinationChoiceSizeCoefficients.csv Destination choice models size term coefficients
FreeParkingEligibility.xls Household free parking eligibility model UEC
IndividualMandatoryTourFrequency.xls Individual mandatory tour frequency model UEC
IndividualNonMandatoryTourFrequency.xls Individual non-mandatory tour frequency model UEC
IndividualNonMandatoryTourFrequency Alternatives.csv Individual non-mandatory tour frequency alternatives by activity part one
IndividualNonMandatoryTourFrequencyExtension Probabilities.csv Individual non-mandatory tour frequency alternatives part two
JointTours.xls Joint tour frequency, party composition, person participation model UECs
Mandatory_accessibility_alts.csv Accessibilities defined for mandatory purpose
ModeChoice.xls Mode choice model UECs (mandatory, non-mandatory, at work subtour)
nonMandatory_accessibility_alts.csv Accessibilities defined for non-mandatory purpose
Parklocation.xls Parking location choice model UEC (mandatory, non-mandatory)
StopDepartureAndDurationStage1.xls Stop timing, stage 1 model UEC
StopDepartureAndDurationStage2.xls Stop timing, stage 2 model UEC
StopDepartureTimeStage1Alternatives.csv Stop timing choice alternatives for stage 1 model
StopDepartureTimeStage2Alternatives.csv Stop timing choice alternatives for stage 2 model
StopDestinationChoice.xls Stop destination choice model UECs (mandatory, maintenance, discretionary, at work subtour)
StopDestinationChoiceAlternativeSample.xls Stop destination choice model UECs sample of alternatives
StopDestinationChoiceCoefficients.csv Stop destination choice models size term coefficients
StopFrequency.xls Stop frequency model UECs (mandatory, maintenance, discretionary, at work subtour)
StopPurposeLookup.csv Stop purpose shares by primary tour purpose, direction, time-of-day, and person type
TourDepartureAndDuration.xls Tour departure time and duration model UECs (mandatory, joint non-mandatory, individual non-mandatory, at work subtour)
TourDepartureAndDurationAlternatives.csv Tour departure time and duration models alternatives
TripDepartHalfHourPercents.csv Trip depart time percents by tour purpose, inbound/outbound, tour hour and trip index
TripModeChoice.xls Trip mode choice model UECs (mandatory, non-mandatory, work subtour)
TravelTime.xls Travel time, distance, toll/fare, transit wait time, transit access time, transit boarding, and transit in-vehicle time skim lookup by mode and time period

Section 6.10 Miscellaneous Files

The highway assignment procedures within the model include the requirement that pass-through heavy duty trucks make use of I-285 rather than the facilities inside I-285. This is done with a database flagging the zones inside and outside of I-285 and is located in the PARAMETERS folder (I285_ZONES.DBF). The format is shown in Table 6-29.

Table 6-28 I-285 Zone File

Column Name Description
1 ZONE Zone Number
2 I285 I-285 flag (1 = inside I-285, 2 = outside I-285)



Atlanta Regional Commission, 2019