columbus · checked on the baseline scenario

Model validation

How closely this study's model reproduces what was observed: traffic counts, federal traffic volumes, commuting and transit ridership. Checked on the baseline scenario, the study's baseline. Published guidelines are shown for reference: they are guidelines, not pass/fail standards, and the manuals that publish them say so.

Independent check the model never saw this dataPartly independent some of this data was used to fit the modelConsistency only the model was fitted to this dataNo observed data a check on the run itself
Traffic counts0.84×modelled ÷ counted VMT vs HPMS0.79×major roads Commute time23.8 vs 3.8minutes, model vs ACS Mode sharer = 0.77car share, tract by tract Transit boardings1.37×modelled ÷ NTD boardings Run quality1.2×10-6assignment relative gap

Traffic counts

Modelled ÷ observed volume

Independent check
0.84×

Across 39 count locations in the study area, the model carries 84 % of the counted traffic in the analysis hour.

Freeways (29)Freeways (29): 0.83×0.83×Multilane arterial (4)Multilane arterial (4): 0.95×0.95×Arterials (6)Arterials (6): 0.97×0.97×1.0 = matches the counts
Technical detail

Independent check: The model never sees traffic counts: demand comes from population, jobs and travel costs, not from the counts.

By count class
Count classNGeh lt5 pctGeh lt10 pctMedian gehSum ratioRmsePct rmse
no_partner0——————
count_defect0——————
reversible_closed0——————
express_hov0——————
wrong_road0——————
out_of_area666.766.70.630.9215313.8
clean3925.646.210.30.8492838.2
Clean counts by road type
Road typeNGeh lt5 pctGeh lt10 pctMedian gehSum ratioRmsePct rmse
freeway2917.234.513.10.831,06835.2
multilane_arterial4255010.90.9534927.7
smaller_arterial666.71003.550.9772.726.6

Headline uses the clean counts; all counts together: 0.85×.

Sources
  • Traffic counts (2025-06-04 to 2025-06-25; 45 counts)

Percent RMSE by volume group

Independent check
38 %

Typical error at a single count location, as a share of the average count.

<500 veh/h (6)<500 veh/h (6): 27 %27 %500-1000 veh/h (3)500-1000 veh/h (3): 35 %35 %1000-2000 veh/h (12)1000-2000 veh/h (12): 32 %32 %2000-4000 veh/h (9)2000-4000 veh/h (9): 47 %47 %>=4000 veh/h (9)>=4000 veh/h (9): 25 %25 %
Published guideline. FHWA (2010) Figure 9.8 compiles %RMSE targets by volume group from Florida, Ohio and Oregon: from about 100 % on links under 5,000 vehicles/day down to about 20 % above 50,000/day (values read off the published chart). Those groups are daily volumes (AADT); this model's counts are one analysis hour, so its groups are not the same links and the comparison is indicative only.
FHWA, Travel Model Validation and Reasonableness Checking Manual, 2nd ed. (FHWA-HEP-10-042, 2010), §9.1.4, Figure 9.8
Technical detail

Independent check: The model never sees traffic counts: demand comes from population, jobs and travel costs, not from the counts.

Clean counts
Volume group (veh/h)Counts%RMSERMSE (veh/h)Modelled ÷ countedMedian GEH
<500626.672.70.973.55
500-1000335.12990.7112.5
1000-20001232.54590.868.61
2000-4000947.51,2520.9222.2
>=4000924.61,3590.8112.5
All counts
Volume group (veh/h)Counts%RMSERMSE (veh/h)Modelled ÷ counted
<500847.91460.77
500-1000335.12990.71
1000-20001627.93980.90
2000-4000947.51,2520.92
>=4000924.61,3590.81
Sources
  • Traffic counts (2025-06-04 to 2025-06-25; 45 counts)

Modelled vs observed, by count

Independent check

45 counts: 6 out of study area, 39 clean.

10101001001,0001,00010,00010,000Counted (veh/h)Modelled (veh/h)tmas:000508:198981409-7904578673-0 (Out of study area): counted 1,571, modelled 1,597tmas:000508:7904578674-198980959-0 (Out of study area): counted 1,852, modelled 1,826tmas:00N210:197356522-1717464295-0 (Out of study area): counted 1,254, modelled 1,258tmas:00N210:375468894-1717472846-0 (Out of study area): counted 1,204, modelled 1,216tmas:00N312:1887637316-359963416-0 (Out of study area): counted 405, modelled 138tmas:00N312:528365952-1887637321-0 (Out of study area): counted 400, modelled 138tmas:000053:200146848-200158550-0 (Clean): counted 180, modelled 203tmas:000053:200158550-200146848-0 (Clean): counted 156, modelled 61.1tmas:000121:229598250-229627704-0 (Clean): counted 5,585, modelled 3,102tmas:000121:229613443-229584346-0 (Clean): counted 3,594, modelled 6,362tmas:000155:198411505-198416213-0 (Clean): counted 1,734, modelled 1,014tmas:000155:198418912-198411526-0 (Clean): counted 2,236, modelled 2,036tmas:000502:229775806-229775861-0 (Clean): counted 1,396, modelled 1,198tmas:000502:319729849-229612435-0 (Clean): counted 2,282, modelled 2,610tmas:000515:229623516-229623560-0 (Clean): counted 217, modelled 229tmas:000515:229623560-229623516-0 (Clean): counted 146, modelled 189tmas:000531:198568392-198317184-0 (Clean): counted 1,188, modelled 1,480tmas:000531:323071123-198567534-0 (Clean): counted 1,084, modelled 694tmas:000539:197344626-197294967-0 (Clean): counted 1,859, modelled 2,279tmas:000539:197358144-197344623-0 (Clean): counted 1,231, modelled 788tmas:000622:319735321-319736957-0 (Clean): counted 753, modelled 345tmas:000622:33154078-12177708326-0 (Clean): counted 993, modelled 978tmas:000628:198618620-434438582-0 (Clean): counted 1,257, modelled 670tmas:000628:434438576-198485100-0 (Clean): counted 1,614, modelled 1,786tmas:000707:198262535-197317562-0 (Clean): counted 2,126, modelled 2,631tmas:000707:332414869-198332486-0 (Clean): counted 1,422, modelled 1,322tmas:000784:200161315-200198647-0 (Clean): counted 488, modelled 575tmas:000784:200198647-200161315-0 (Clean): counted 455, modelled 343tmas:000N97:229606662-12347447295-0 (Clean): counted 2,524, modelled 1,523tmas:000N97:429379698-229619323-0 (Clean): counted 2,300, modelled 1,231tmas:000N99:2654524523-2654524528-0 (Clean): counted 4,672, modelled 3,864tmas:000N99:2654524631-2654524711-0 (Clean): counted 2,944, modelled 1,710tmas:00N100:230247700-325091910-0 (Clean): counted 6,065, modelled 6,614tmas:00N100:325091671-229597868-0 (Clean): counted 4,024, modelled 3,511tmas:00N101:230270893-333563778-0 (Clean): counted 2,974, modelled 2,226tmas:00N101:5233358972-229626111-0 (Clean): counted 2,755, modelled 1,406tmas:00N102:229638975-229630444-0 (Clean): counted 5,335, modelled 4,232tmas:00N102:229873892-229594682-0 (Clean): counted 5,812, modelled 4,075tmas:00N106:229611298-230272534-0 (Clean): counted 5,008, modelled 4,159tmas:00N214:229607217-427855703-0 (Clean): counted 1,774, modelled 793tmas:00N214:229613130-229821438-0 (Clean): counted 1,258, modelled 1,260tmas:00N221:1837763255-349011994-0 (Clean): counted 6,541, modelled 4,630tmas:00N221:349011964-229600358-0 (Clean): counted 6,772, modelled 5,970tmas:00N310:13741132547-199378142-0 (Clean): counted 1,142, modelled 1,254tmas:00N310:199378840-13265634557-0 (Clean): counted 804, modelled 486
Clean countsOther classes (left out of the headlines)
Technical detail

Independent check: The model never sees traffic counts: demand comes from population, jobs and travel costs, not from the counts.

Modelled side: assigned demand + background preload (truck_and_band); two-way counts sum the edge and its partner (reverse edge or opposite carriageway); a one-way street is scored alone.

Count classes (each count gets the first that applies)
Count classCountsWhat it means
Two-way, no partner carriageway0A count of both directions with no opposite carriageway to pair it with: a ramp, a freeway with none found, or a divided road turning undivided at the count. It is not scored, because the model could only compare it with part of the road.
Faulty count0The count's own records show a fault: one lane reads 0 in every hour, so the total misses it, or the count is doubled (every value even, or more vehicles in one lane than a lane can carry).
Reversible lane, closed0A lane closed in this direction at the count hour, such as a reversible express lane, so there is no traffic to compare.
Express / HOV lane0On or beside an express or HOV lane. Their traffic depends on tolls and occupancy rules, so they are scored apart.
Matched to the wrong road0Matched to the wrong road: more traffic than the matched road can carry, or a station whose directions matched different roads.
Out of study area6Outside the study area, where most traffic comes from outside the model.
Clean39Everything else: the fair test of the model, used in the headlines.
Counts left out of the headlines (6)
CountClassWhy it is left outCountedModelled
tmas:000508:198981409-7904578673-0Out of study area1.9 km outside the study area1,5711,597
tmas:000508:7904578674-198980959-0Out of study area1.9 km outside the study area1,8521,826
tmas:00N210:197356522-1717464295-0Out of study area4.1 km outside the study area1,2541,258
tmas:00N210:375468894-1717472846-0Out of study area4.1 km outside the study area1,2041,216
tmas:00N312:1887637316-359963416-0Out of study area3.6 km outside the study area405138
tmas:00N312:528365952-1887637321-0Out of study area3.6 km outside the study area400138
Largest differences (GEH)
CountCountedModelledGEHClass
tmas:000121:229613443-229584346-03,5946,36239.2clean
tmas:000121:229598250-229627704-05,5853,10237.7clean
tmas:00N221:1837763255-349011994-06,5414,63025.6clean
tmas:00N102:229873892-229594682-05,8124,07524.7clean
tmas:00N101:5233358972-229626111-02,7551,40629.6clean
Sources
  • Traffic counts (2025-06-04 to 2025-06-25; 45 counts)

Peak-direction share at paired stations

Independent check
58.4 % vs 56.3 %

At 19 count stations with both directions clean, 56.3 % of the counted traffic runs in the busier (peak) direction; the model puts 58.4 % there. Typical station error 10.4 percentage points.

Freeways (14)Freeways (14): 57.3 %57.3 %Freeways (14), observed: 56.2 %56.2 %Multilane arterial (2)Multilane arterial (2): 73.5 %73.5 %Multilane arterial (2), observed: 59.6 %59.6 %Arterials (3)Arterials (3): 62.9 %62.9 %Arterials (3), observed: 53.9 %53.9 %50 % = even split
ModelCounted
Technical detail

Independent check: The model never sees traffic counts: demand comes from population, jobs and travel costs, not from the counts.

Difference, model − counted
2.1 pp
Modelled ÷ counted, peak direction
0.88×
Modelled ÷ counted, counter-peak direction
0.80×
Two-way counts (no split)
0

The peak direction is the one with more counted traffic. The two ratios tell a level error (both off together) from a split error (the two apart).

By road type
Road typeStationsCounted peak shareModelled peak shareDifference (pp)Median station error (pp)Modelled ÷ counted, peakModelled ÷ counted, counter-peak
Freeways1456.2 %57.3 %1.138.680.850.81
Multilane arterial259.6 %73.5 %13.913.81.180.63
Arterials353.9 %62.9 %9.0510.91.140.78
Paired stations
StationRoad typePeak / counterCounted peakCounted counterModelled peakModelled counterCounted peak share (%)Modelled peak share (%)Error (pp)
000053Arterials5 / 118015620361.153.676.823.3
000121Freeways3 / 75,5853,5943,1026,36260.832.8-28.1
000155Freeways3 / 72,2361,7342,0361,01456.366.710.4
000502Freeways7 / 32,2821,3962,6101,1986268.56.50
000515Arterials3 / 721714622918959.854.8-5
000531Freeways7 / 31,1881,0841,48069452.368.115.8
000539multilane_arterial7 / 31,8591,2312,27978860.274.314.1
000622Freeways7 / 399375397834556.973.917
000628Freeways7 / 31,6141,2571,78667056.272.716.5
000707Freeways7 / 32,1261,4222,6311,32259.966.56.60
000784Arterials5 / 148845557534351.762.610.9
000N97Freeways5 / 12,5242,3001,5231,23152.355.33
000N99Freeways1 / 54,6722,9443,8641,71061.369.38
00N100Freeways3 / 76,0654,0246,6143,51160.165.35.20
00N101Freeways5 / 12,9742,7552,2261,40651.961.39.40
00N102Freeways1 / 55,8125,3354,0754,23252.149.1-3.10
00N214Freeways5 / 11,7741,2587931,26058.538.6-19.9
00N221Freeways1 / 56,7726,5415,9704,63050.956.35.50
00N310multilane_arterial1 / 51,1428041,25448658.772.113.4
Directional stations not paired (4)
SourceStationWhy it is not paired
tmas000508partner not clean (out_of_area)
tmas00N106partner not matched
tmas00N210partner not clean (out_of_area)
tmas00N312partner not clean (out_of_area)
Sources
  • Traffic counts (2025-06-04 to 2025-06-25; 45 counts)

GEH statistic

Independent checkAdvanced
26 % below 5

Share of clean count locations whose GEH is below 5.

Freeways (29)Freeways (29): 17 %17 %Multilane arterial (4)Multilane arterial (4): 25 %25 %Arterials (6)Arterials (6): 67 %67 %
Published guideline. GEH below 5 on more than 85 % of links. TAG applies this to models whose trip tables may have been adjusted to counts (matrix estimation); a demand model without that step should not be expected to reach it.
UK DfT, TAG Unit M3.1 Highway Assignment Modelling (May 2026), §3.3.10–3.3.11, Table 2
Technical detail

Independent check: The model never sees traffic counts: demand comes from population, jobs and travel costs, not from the counts.

GEH below 10, clean
46 %
Median GEH, clean
10.3
By count class
Count classNGeh lt5 pctGeh lt10 pctMedian gehSum ratioRmsePct rmse
no_partner0——————
count_defect0——————
reversible_closed0——————
express_hov0——————
wrong_road0——————
out_of_area666.766.70.630.9215313.8
clean3925.646.210.30.8492838.2
Clean counts by road type
Road typeNGeh lt5 pctGeh lt10 pctMedian gehSum ratioRmsePct rmse
freeway2917.234.513.10.831,06835.2
multilane_arterial4255010.90.9534927.7
smaller_arterial666.71003.550.9772.726.6
Sources
  • Traffic counts (2025-06-04 to 2025-06-25; 45 counts)

TAG flow criteria

Independent checkAdvanced
33 %

Share of the 39 clean counts within TAG's flow criteria.

Published guideline. More than 85 % of links within 100 veh/h below 700 veh/h, within 15 % at 700–2,700 veh/h, and within 400 veh/h above 2,700 veh/h. Defined on hourly flows, the model's own unit. As with GEH, TAG's models may have had matrix estimation.
UK DfT, TAG Unit M3.1 Highway Assignment Modelling (May 2026), §3.3.10–3.3.11, Table 2
Technical detail

Independent check: The model never sees traffic counts: demand comes from population, jobs and travel costs, not from the counts.

All counts
38 %
Sources
  • Traffic counts (2025-06-04 to 2025-06-25; 45 counts)

Vehicle-miles travelled

Regional VMT vs HPMS

Independent check
0.79×

Modelled vehicle-km on freeways, arterials and major collectors, against federal HPMS traffic volumes.

Published guideline. Florida's guideline, quoted by FHWA (2010): regional VMT within ±5 % (acceptable) or ±2 % (preferable). Freeways, arterials and major collectors only; local roads and ramps have no HPMS counterpart.
FHWA, Travel Model Validation and Reasonableness Checking Manual, 2nd ed. (FHWA-HEP-10-042, 2010), §9.1.4
Technical detail

Independent check: HPMS traffic volumes are not used to build or calibrate travel demand. They set the background through-traffic and truck layer, which is counted on both sides.

Model
3,693,492 veh-km per analysis hour
HPMS
4,701,862 veh-km per analysis hour
Passenger demand only
0.71×

Observed side uses TMAS-measured per-cell K-factors from this study's own volumes (provenance.hour_factor). Trucks still carry the assumed truck_hour_factor. Caveat: the measurement uses whatever months observed_counts fetched — early summer on studies to date — and summer mornings carry no school traffic, so school-year K is likely somewhat higher. Direction known, size unmeasured.

Sources
  • FHWA Highway Performance Monitoring System (HPMS) (vintage 2024)
  • Hour factor (AADT → analysis hour) (measured)

VMT by road type vs HPMS

Independent check
0.83×, 0.73×

Modelled ÷ HPMS vehicle-km, by road type (freeways and expressways; arterials and major collectors), on the matched basis; the thinner bar is the netted ratio.

Freeways and expresswaysFreeways and expressways: 0.83×0.83×Freeways and expressways, netted: 0.85×0.85×Arterials and major collectorsArterials and major collectors: 0.73×0.73×Arterials and major collectors, netted: 0.82×0.82×Local roads and unclassified *Local roads and unclassified *: 0.65×0.65×Local roads and unclassified *, netted: 4.12×4.12×1.0 = matches HPMS
Matched (headline)Netted

* No HPMS counterpart for most of its length; left out of the regional ratio.

Published guideline. FHWA (2010) Table 9.2 compiles VMT guidelines by functional class from five agencies: freeways within 6–7 %; principal arterials 7–15 %; minor arterials 10–15 %; collectors 15–25 %. This comparison groups principal arterials, minor arterials and major collectors into one cell, so its guideline is the range across those classes. HPMS does not inventory local roads; that row is a coverage artifact, not a finding.
FHWA, Travel Model Validation and Reasonableness Checking Manual, 2nd ed. (FHWA-HEP-10-042, 2010), §9.1.4, Table 9.2
Technical detail

Independent check: HPMS traffic volumes are not used to build or calibrate travel demand. They set the background through-traffic and truck layer, which is counted on both sides.

Road typeModel (veh-km per analysis hour)HPMSRatioNettedGrossPassenger only
Freeways and expressways2,093,3342,460,6100.830.850.770.87
Arterials and major collectors1,829,9932,241,2520.730.820.810.82
Local roads and unclassified247,29959,9710.654.123.784.18

Observed side uses TMAS-measured per-cell K-factors from this study's own volumes (provenance.hour_factor). Trucks still carry the assumed truck_hour_factor. Caveat: the measurement uses whatever months observed_counts fetched — early summer on studies to date — and summer mornings carry no school traffic, so school-year K is likely somewhat higher. Direction known, size unmeasured.

N sections cachedN sections in areaN edges modelN edges wholly outside areaModel vmt share in areaN edges boundN edges full basisN edges pruned floorN edges eligibleBind ratePreload availableDisposition available
Coverage34,34821,51387,1318,1700.9336,171214,391127,26047,7240.76yesyes
Sources
  • FHWA Highway Performance Monitoring System (HPMS) (vintage 2024)
  • Hour factor (AADT → analysis hour) (measured)

Congestion

Volume-to-capacity distribution

No observed dataAdvanced
0.2 %

Share of directional road-km at a volume-to-capacity ratio of 0.85 or more in the analysis hour. A reasonableness check: no observed data.

CollectorsCollectors: 0.1 %0.1 %FreewaysFreeways: 2.0 %2.0 %Local roadsLocal roads: 0.1 %0.1 %Multilane arterialMultilane arterial: 0.4 %0.4 %RampsRamps: 0.3 %0.3 %ArterialsArterials: 0.3 %0.3 %
Technical detail

No observed data: A reasonableness check: there is no observed side.

Road typeDirectional kmV/C ≥ 0.85V/C ≥ 1.0
collector13,9110.0010.000
freeway1,8550.0200.003
local10,6190.0010.000
multilane_arterial1,9010.0040.002
ramp42.90.0030.000
smaller_arterial2,0130.0030.001
all30,3420.0020.001

directional road-km; assigned + background vehicles over directional capacity.

Trip lengths

Work trip lengths vs LODES

UnavailableAdvanced

The model's work trips by origin and destination were not saved for this study ([demand.balancing] is off).

Commute mode share

Commute mode share across the region

Partly independent
r = 0.77

How closely the model's car share of work trips follows the ACS from tract to tract (correlation weighted by commuters). Calibration fits the region's shares, not this pattern.

Car r = 0.77
0 %50 %100 %<1k — Model: 99.1 %<1k — ACS: 97.5 %<1k1k–2.5k — Model: 97.7 %1k–2.5k — ACS: 97.0 %1k–2.5k2.5k–5k — Model: 96.0 %2.5k–5k — ACS: 95.5 %2.5k–5k5k–10k — Model: 93.9 %5k–10k — ACS: 92.5 %5k–10k10k–20k — Model: 86.5 %10k–20k — ACS: 86.5 %10k–20k≥20k — Model: 77.2 %≥20k — ACS: 54.2 %≥20k
Transit r = 0.69
0 %4 %8 %<1k — Model: 0.1 %<1k — ACS: 0.3 %<1k1k–2.5k — Model: 0.7 %1k–2.5k — ACS: 1.0 %1k–2.5k2.5k–5k — Model: 1.4 %2.5k–5k — ACS: 1.3 %2.5k–5k5k–10k — Model: 2.9 %5k–10k — ACS: 2.8 %5k–10k10k–20k — Model: 4.7 %10k–20k — ACS: 4.3 %10k–20k≥20k — Model: 7.0 %≥20k — ACS: 7.5 %≥20k
Walk r = 0.70
0 %20 %40 %<1k — Model: 0.6 %<1k — ACS: 1.2 %<1k1k–2.5k — Model: 1.1 %1k–2.5k — ACS: 1.2 %1k–2.5k2.5k–5k — Model: 2.0 %2.5k–5k — ACS: 2.0 %2.5k–5k5k–10k — Model: 2.5 %5k–10k — ACS: 2.6 %5k–10k10k–20k — Model: 7.8 %10k–20k — ACS: 6.7 %10k–20k≥20k — Model: 14.5 %≥20k — ACS: 35.6 %≥20k
Bicycle r = 0.36
0 %1 %2 %<1k — Model: 0.1 %<1k — ACS: 0.1 %<1k1k–2.5k — Model: 0.2 %1k–2.5k — ACS: 0.1 %1k–2.5k2.5k–5k — Model: 0.3 %2.5k–5k — ACS: 0.2 %2.5k–5k5k–10k — Model: 0.4 %5k–10k — ACS: 0.5 %5k–10k10k–20k — Model: 0.6 %10k–20k — ACS: 1.3 %10k–20k≥20k — Model: 0.9 %≥20k — ACS: 1.7 %≥20k

Work-trip mode share by residential density (people per sq mi), model vs ACS, with the ACS 90 % margin of error.

ModelACS
Technical detail

Partly independent: Calibration fits the region's work mode shares to this same ACS table, so the regional level is consistency-only. How the shares vary from tract to tract is not fitted.

ModeModel modesWeighted correlationTracts
carCAR, CAR_NONHH0.77521
transitTRANSIT0.69521
walkWALK0.70521
bicycleBICYCLE0.36521
ModePeople / sq miTractsModel shareACS shareACS ± (90 %)ACS commuters
car<1,0001520.990.970.023223,269
car1,000–2,500870.980.970.034152,479
car2,500–5,0001500.960.950.025279,667
car5,000–10,0001150.940.930.030200,415
car10,000–20,000130.870.870.07128,312
car≥20,00060.770.540.05210,273
transit<1,0001520.0010.0030.001223,269
transit1,000–2,500870.0070.0100.002152,479
transit2,500–5,0001500.0140.0130.002279,667
transit5,000–10,0001150.0290.0280.003200,415
transit10,000–20,000130.0470.0430.01228,312
transit≥20,00060.0700.0750.01810,273
walk<1,0001520.0060.0120.002223,269
walk1,000–2,500870.0110.0120.002152,479
walk2,500–5,0001500.0200.0200.002279,667
walk5,000–10,0001150.0250.0260.003200,415
walk10,000–20,000130.0780.0670.01228,312
walk≥20,00060.150.360.02710,273
bicycle<1,0001520.0010.0010.001223,269
bicycle1,000–2,500870.0020.0010.001152,479
bicycle2,500–5,0001500.0030.0020.001279,667
bicycle5,000–10,0001150.0040.0050.001200,415
bicycle10,000–20,000130.0060.0130.00528,312
bicycle≥20,00060.0090.0170.00910,273
Car
ACS drove alone + carpooled + motorcycle vs model car + car as passenger (CAR_NONHH)
Weighting
tract ACS commuters × share of the tract inside the zones
Density
2020 Census population per square mile of land
Sources
  • ACS 5-year estimates, census tracts (B08301) (vintage 2018–2022)
  • 2020 Census block population (density, crosswalk) (vintage 2020)

Transit

Transit boardings vs NTD

Independent check
1.37×

Modelled boardings in the analysis period ÷ NTD's average weekday × the share of weekday transit trips in that period (11.3 %). 6,182 modelled, 4,528 observed.

Central Ohio Tran…, busCentral Ohio Tran…, bus: 6,1106,110Central Ohio Tran…, bus, observed: 4,5014,501Licking County, O…, busLicking County, O…, bus: 72.772.7Licking County, O…, bus, observed: 26.726.7
ModelNTD × period share
Published guideline. Florida's guideline, quoted by FHWA (2010): regional estimated-over-observed transit boardings within ±9 % (acceptable) or ±3 % (preferable). FHWA adds that when the trips come from the model's own mode choice rather than an observed rider survey, as here, "desired criteria might be less stringent" (§9.2.4).
FHWA, Travel Model Validation and Reasonableness Checking Manual, 2nd ed. (2010), §9.2.4, Table 9.9
Technical detail

Independent check: the model never saw this data.

AgencyNTD IDMode groupCoverageReporterModel (period)NTD (avg weekday)NTD estimated
Central Ohio Transit Authority50016busfullFull Reporter6,11039,854no
Licking County, Ohio, dba: Licking County Transit50163busfullFull Reporter72.7236no
Period share
11.3 % (NHTS 2017 (national, weekday trips); 90 % interval 10.3 %–12.2 %)
Peaking caveat
2016–17 peaking, before the pandemic; transit peaks have flattened since, so the share may run high
NTD report year
2,025
Left out
demand response, vanpool, taxi, jitney (the model does not route them)

transit trips × rides on the routed path; NTD counts unlinked trips (boardings)

Sources
  • National Transit Database (FTA), annual Service by mode and time period (vintage report year 2025; data.transportation.gov wwdp-t4re; fetched 2026-11-07)
  • NHTS 2017 (weekday transit trips' arrival-hour profile) (vintage 2016–2017)
  • NTD agency match (ntd_match.toml) (vintage 2026-11-06; connector-rollout session, on Taylor's go-ahead)

Transit passenger-miles vs NTD

Independent check
1.09×

Modelled passenger-miles in the analysis period ÷ NTD's average weekday × the share of weekday transit trips in that period (11.3 %). 22,038 modelled, 20,224 observed.

Central Ohio Tran…, busCentral Ohio Tran…, bus: 21,84421,844Central Ohio Tran…, bus, observed: 20,09420,094Licking County, O…, busLicking County, O…, bus: 194194Licking County, O…, bus, observed: 131131
ModelNTD × period share
Published guideline. FHWA (2010) suggests the regional VMT guideline "might be considered" for passenger-miles: e.g. ±5 %. FHWA adds that when the trips come from the model's own mode choice rather than an observed rider survey, as here, "desired criteria might be less stringent" (§9.2.4).
FHWA, Travel Model Validation and Reasonableness Checking Manual, 2nd ed. (2010), §9.2.4
Technical detail

Independent check: the model never saw this data.

AgencyNTD IDMode groupCoverageReporterModel (period)NTD (avg weekday)NTD estimated
Central Ohio Transit Authority50016busfullFull Reporter21,844177,904no
Licking County, Ohio, dba: Licking County Transit50163busfullFull Reporter1941,157no
Period share
11.3 % (NHTS 2017 (national, weekday trips); 90 % interval 10.3 %–12.2 %)
Peaking caveat
2016–17 peaking, before the pandemic; transit peaks have flattened since, so the share may run high
NTD report year
2,025
Left out
demand response, vanpool, taxi, jitney (the model does not route them)

Routing keeps each ride's in-vehicle time, not its distance. Ride miles are that time × the route's average scheduled speed, so a ride on the route's slow downtown end is counted a little long, and one on its fast outer end a little short.

Sources
  • National Transit Database (FTA), annual Service by mode and time period (vintage report year 2025; data.transportation.gov wwdp-t4re; fetched 2026-11-07)
  • NHTS 2017 (weekday transit trips' arrival-hour profile) (vintage 2016–2017)
  • NTD agency match (ntd_match.toml) (vintage 2026-11-06; connector-rollout session, on Taylor's go-ahead)

Average transit trip length

Independent checkAdvanced
3.56 vs 4.47 mi

Average miles per boarding, model vs NTD (passenger-miles ÷ boardings).

busbus: 3.56 mi3.56 mibus, observed: 4.47 mi4.47 mi
ModelNTD
Technical detail

Independent check: the model never saw this data.

Mode groupModel (mi)NTD (mi)Includes partial agencies
bus3.564.47no

A ratio, so it needs no period scaling; partial-coverage agencies are included and flagged.

Sources
  • National Transit Database (FTA), annual Service by mode and time period (vintage report year 2025; data.transportation.gov wwdp-t4re; fetched 2026-11-07)
  • NHTS 2017 (weekday transit trips' arrival-hour profile) (vintage 2016–2017)
  • NTD agency match (ntd_match.toml) (vintage 2026-11-06; connector-rollout session, on Taylor's go-ahead)

Commute time

Commute time

Independent check
23.8 vs 3.8 min

Mean work trip 23.8 min in the model; 3.8 min ± 0.1 reported in the ACS. Coincidence of the two distributions: 0.84.

0 %10 %20 %<5 — Model: 2.5 %<5 — ACS: 2.4 %<55–9 — Model: 9.1 %5–9 — ACS: 9.0 %5–910–14 — Model: 15.1 %10–14 — ACS: 13.5 %10–1415–19 — Model: 18.9 %15–19 — ACS: 16.5 %15–1920–24 — Model: 16.9 %20–24 — ACS: 18.0 %20–2425–29 — Model: 13.0 %25–29 — ACS: 9.5 %25–2930–34 — Model: 9.0 %30–34 — ACS: 14.0 %30–3435–39 — Model: 4.8 %35–39 — ACS: 3.5 %35–3940–44 — Model: 3.0 %40–44 — ACS: 3.6 %40–4445–59 — Model: 5.3 %45–59 — ACS: 5.7 %45–5960–89 — Model: 2.1 %60–89 — ACS: 2.8 %60–89≥90 — Model: 0.3 %≥90 — ACS: 1.4 %≥90
ModelACS
Technical detail

Independent check: the model never saw this data.

MinutesModel shareACS shareACS ± (90 %)
<50.0250.0240.002
5–90.0910.0900.003
10–140.150.130.003
15–190.190.170.004
20–240.170.180.004
25–290.130.0950.003
30–340.0900.140.003
35–390.0480.0350.002
40–440.0300.0360.002
45–590.0530.0570.002
60–890.0210.0280.001
≥900.0030.0140.001
ACS mean basis
county (B08136 ÷ B08303), coverage-weighted
Model work trips in the period
93,846
Sources
  • ACS 5-year estimates, census tracts (B08303) (vintage 2018–2022)
  • ACS 5-year estimates, counties (B08136, B08303) (vintage 2018–2022)

Commute time by mode

Independent check
car 5.95×, transit 77.79×, walk 20.27×

Mean work trip time by mode, model ÷ ACS.

CarCar — ACS: 3.9 min ± 0.1 minCar — Model: 23.2 minTransitTransit — ACS: 0.8 min ± 0.4 minTransit — Model: 62.3 minWalkWalk — ACS: 1.1 min ± 0.2 minWalk — Model: 21.7 min0 min40 min80 min
ModelACS, with 90 % margin of error
Technical detail

Independent check: the model never saw this data.

ModeModel (min)ACS (min)ACS ± (90 %)RatioModel trips (period)ACS workers
car23.23.890.0935.9590,185847,040
transit62.30.800.3977.81,38213,531
walk21.71.070.2020.31,79220,780

ACS commute times are self-reported and door to door. They cluster at 15, 30 and 60 minutes and run above a network travel time, which for car leaves out parking search and the walk at each end. Read the shape before the level.

ACS car is car, truck or van (drove alone and carpooled); its bicycle time is lumped with taxi, motorcycle and other means, so there is no bicycle row. The ACS means are county-level: tract-level aggregate times are mostly suppressed.

Sources
  • ACS 5-year estimates, counties (B08136, B08301) (vintage 2018–2022)

Commute-time distribution by mode

Partly independent

Share of work trips by commute time, per mode. Coincidence is the overlap of the two distributions (1 = identical).

Car coincidence 0.83
0 %10 %20 %<10 — Model: 11.9 %<10 — ACS: 10.7 %<1010–14 — Model: 15.3 %10–14 — ACS: 13.3 %15–19 — Model: 18.9 %15–19 — ACS: 16.8 %15–1920–24 — Model: 17.3 %20–24 — ACS: 18.4 %25–29 — Model: 13.3 %25–29 — ACS: 9.8 %25–2930–34 — Model: 9.1 %30–34 — ACS: 14.2 %35–44 — Model: 7.6 %35–44 — ACS: 7.3 %35–4445–59 — Model: 5.1 %45–59 — ACS: 5.7 %≥60 — Model: 1.6 %≥60 — ACS: 3.8 %≥60
Transit coincidence 0.44
0 %30 %60 %<10 — Model: 0.0 %<10 — ACS: 1.6 %<1010–14 — Model: 0.5 %10–14 — ACS: 6.0 %15–19 — Model: 1.3 %15–19 — ACS: 7.5 %15–1920–24 — Model: 2.4 %20–24 — ACS: 13.2 %25–29 — Model: 3.6 %25–29 — ACS: 7.1 %25–2930–34 — Model: 4.7 %30–34 — ACS: 16.2 %35–44 — Model: 13.5 %35–44 — ACS: 8.8 %35–4445–59 — Model: 22.4 %45–59 — ACS: 11.4 %≥60 — Model: 51.5 %≥60 — ACS: 28.0 %≥60
Walk coincidence 0.43 Consistency only
0 %25 %50 %<10 — Model: 7.6 %<10 — ACS: 41.3 %<1010–14 — Model: 17.0 %10–14 — ACS: 21.8 %15–19 — Model: 37.8 %15–19 — ACS: 14.0 %15–1920–24 — Model: 8.0 %20–24 — ACS: 9.7 %25–29 — Model: 7.5 %25–29 — ACS: 2.5 %25–2930–34 — Model: 6.1 %30–34 — ACS: 5.9 %35–44 — Model: 11.8 %35–44 — ACS: 1.3 %35–4445–59 — Model: 3.4 %45–59 — ACS: 2.5 %≥60 — Model: 0.8 %≥60 — ACS: 1.0 %≥60
ModelACS
Technical detail

Partly independent: Calibration fits work walk durations to this same ACS table, so the walk rows are consistency-only; car and transit are independent.

ModeCoincidenceACS workersIndependence
car0.83847,575independent
transit0.4413,476independent
walk0.4320,711consistency

ACS commute times are self-reported and door to door. They cluster at 15, 30 and 60 minutes and run above a network travel time, which for car leaves out parking search and the walk at each end. Read the shape before the level.

Sources
  • ACS 5-year estimates, census tracts (B08134) (vintage 2018–2022)

Run quality

Assignment convergence

No observed data
1.2×10-6

Relative gap when the assignment stopped, after 2 iterations of tapb; target 1.0×10-5. Converged.

Published guideline. A relative gap of 10⁻⁴ (0.01 %) for link flows stable enough to compare scenarios; TAG asks for below 0.1 % on a base-year model.
Boyce, Ralevic-Dekic & Bar-Gera, "Convergence of Traffic Assignments: How Much Is Enough?", Journal of Transportation Engineering 130(1):49–55 (2004); UK DfT, TAG Unit M3.1 Highway Assignment Modelling (May 2026), Table 4
Technical detail

No observed data: a check on the run itself.

Relative gap as the assignment solver reports it: total travel time on the loaded network minus the travel time if every trip took its current shortest path, divided by the former. Zero is a perfect user equilibrium.

Demand-feedback convergence

No observed data
Converged at iteration 2

Demand and assignment re-run until travel times and the trip table stop changing.

stopping tolerance10-510-1Iteration 1: 2.77e-021Iteration 2: 6.49e-052

Change in the trip table between outer iterations (RMSE ÷ mean), log scale.

Technical detail

No observed data: a check on the run itself.

IterationAssignment gapTravel-time changeTrip-table changeTotal-trip changeCriteria met
10.0000.0000.0280.001no
20.0000.0000.0000.000yes
Time gap tol
0.025
Od rmse tol
0.005
Total trips tol
0.005
Max outer
10
Min outer
2

Noise floor

Unavailable

The noise floor was not measured for this study ([assignment.feedback] measure_noise_floor is off).

Mode-choice calibration residual

Consistency only
residual 0.046

Converged at iteration 2 of 2; tolerance 0.050. Detail on the Calibration page.

Technical detail

Consistency only: Calibration fits these targets by construction.

Coverage

No observed data
822 zones

13 of 835 zones were too sparse to model; their residents and destinations moved to a neighbouring zone, not lost. Every home-based trip was assigned a destination. Every trip home was placed.

Technical detail

No observed data: a check on the run itself.

N zones original
835
N zones retained
822
N zones dropped
13
Pop before
2,071,589
Pop after
2,071,589
Snap method
nearest_zone
Generation pool period
247,786
Assigned person trips period
247,786
Unassigned person trips period
-0.003
Relative gap
0.000
Status
ok
Generated
54,609
Distributed
54,609
Unreachable
-0.001
Unreachable share
-0.000
Max column gap rel
0.000

What this was checked against

No observed data

12 observed sources.

SourceVintageFromToUsed by
Traffic counts—2025-06-042025-06-25A3, A5, A7, A8, A1, A2, A9
FHWA Highway Performance Monitoring System (HPMS)2024——B1, B2
Hour factor (AADT → analysis hour)———B1, B2
ACS 5-year estimates, census tracts (B08301)2018–2022——E2
2020 Census block population (density, crosswalk)2020——E2
National Transit Database (FTA), annual Service by mode and time periodreport year 2025——F1, F2, F3
NHTS 2017 (weekday transit trips' arrival-hour profile)2016–2017——F1, F2, F3
NTD agency match (ntd_match.toml)2026-11-06——F1, F2, F3
ACS 5-year estimates, census tracts (B08303)2018–2022——G1
ACS 5-year estimates, counties (B08136, B08303)2018–2022——G1
ACS 5-year estimates, counties (B08136, B08301)2018–2022——G2
ACS 5-year estimates, census tracts (B08134)2018–2022——G3