Data quality report

Region: Northern California

Season: Northern California Fall 2019 Saturday

Report generated: 2021-08-21




https://www.replicahq.com

support@replicahq.com


Review the Overall Summary

Table of contents

About this report

This report describes how Replica model compares to other data sources describing movement in the region, including relevant Census surveys aggregates and observed volumes of traffic, transit boardings and non-motorized trip counts in the region. Replica describes a typical week of travel for a specific three-month (quarter) period, and comparisons are made with the data collected within the relevant period and aggregated to represent a typical day of travel.
Each section of the report provides details on the accuracy of the model within the relevant comparison category.

Origin-Destination Flows

This section compares overall county-to-county work commute characteristics against Census Transportation Planning Product (CTPP) data. Replica models all trips by residents of the core modeling region as well as trips by residents of the extended region who work in the core. A comparison of the distribution of number of departures within each hour by county of origin is provided.
Note: Replica counts are scaled so that the total number of trips matches the CTPP, in order to account for discrepancies between average daily travel patterns and self-reported survey responses.
CTPP movements, Figure 1: Commute departures by hour by county

Notes

  • CTPP 2012-2016 is used as the source of commute volumes for county-to-county and significant tract-to-tract flows, as well as reported departure times.
  • Commute flows should only be compared with CTPP for typical weekdays (not weekends).
Note: Error and Bound numbers for this section are 1 - p, where p is the correlation coefficient.
Error Bound ✓
Subcategory Bucket
Commute Departures per Hour By County nan 0.100000 NA

Traffic

Auto, Figure 1: Map of the traffic volumes sensor locations for the simulated region/season.

Daily totals

Auto, Figure 2: Total daily volumes: by road type (top) and volume (bottom)
Error Bound ✓
Bucket
<10k daily 0.419706 0.500000 ✓
10-20k daily 0.236962 0.350000 ✓
20-40k daily 0.130518 0.250000 ✓
40-60k daily 0.122318 0.200000 ✓
60-80k daily 0.095294 0.150000 ✓
80-100k daily 0.084703 0.120000 ✓
>100k daily 0.110537 0.100000 ≈

Hourly totals

Total hourly volumes are generally less accurate in the night hours. Due to privacy considerations Replica does not reproduce most of the rare nighttime (not “typical”) trips.
Error Bound ✓
Bucket
Arterials hourly 0.309278 nan NA
Freeways hourly 0.224317 nan NA
Auto, Figure 3: Hourly volumes on major (>=50,000 daily volume) roadways

Average Speeds by Hour

This section reports on Replica traffic speeds on different categories of roadways as compared to the observed data. This comparison focuses only on peak commute hours: 5AM to 10AM and 3PM to 7PM.
Auto, Figure 4: Hourly auto speeds
Error Bound ✓
Subcategory Bucket
Morning Peak Other roads nan 0.300000 NA
Evening Peak Other roads nan 0.300000 NA
Morning Peak Arterials nan 0.150000 NA
Evening Peak Arterials nan 0.150000 NA
Morning Peak Freeways nan 0.100000 NA
Evening Peak Freeways nan 0.100000 NA

Notes

  • Observed volume counts may contain outliers due to ambiguities in sensor locations and malfunctioning sensor hardware.
  • Detailed comparisons are available in multiple formats (csv, geojson, shp) in the Ground Truth section of the Replica downloads page (https://my.replicahq.com/downloads).

Public Transportation

Daily totals

Public Transit, Figure 1: Total daily number of boardings: by volume (top), route type (middle), and agency (bottom)

Notes

  • Public transit ridership accuracy is reported as percentage error of total ridership per volume category and service type.
  • Per-line comparisons are available in multiple formats (csv, geojson, shp) in the Ground Truth section of the Replica downloads page (https://my.replicahq.com/downloads).
Error Bound ✓
Category Subcategory Bucket
Transit Regionwide Total Daily Trips nan 0.050000 NA
Daily Boardings 0.087515 0.050000
Daily Volumes <2000 daily 0.219205 1.000000 ✓
2000-5000 daily 0.244949 0.500000 ✓
5000-10000 daily 0.205924 0.300000 ✓
10000-20000 daily 0.172848 0.200000 ✓
>20000 daily 0.273966 0.150000

On-Demand Transportation: TNC + Taxi

Region-wide on-demand trips per hour

On-demand auto, Figure 1: Total number of person trips by hour

Daily Person Trips by origin/destination tract

On-demand auto, Figure 2: Total daily person trips by origin tract (top) and destination tract (bottom)

On demand origin/destinations by tract/hour

On-demand auto, Figure 3: Hourly person trips by origin tract (top) and destination tract (bottom)
Error Bound ✓
Subcategory Bucket
By hour Regionwide 0.285909 0.250000
Daily Volumes by Origin Tract <1000 daily 0.212233 inf ✓
1000+ daily 0.023222 0.250000 ✓
Daily Volumes by Destination Tract <1000 daily 0.233055 inf ✓
1000+ daily 0.030115 0.250000 ✓
Hourly Volumes by Origin Tract <1000 daily 0.615766 nan NA
1000+ daily 0.217105 nan NA
Hourly Volumes by Destination Tract <1000 daily 0.570275 nan NA
1000+ daily 0.181206 nan NA

Commercial Vehicles

In this section commercial freight traffic volumes represented in Replica are broken out separately and compared to the observed volumes of trucks in a select number of count locations where data exists.

Daily totals

Freight, Figure 1: Total daily commercial freight traffic by volume and vehicle class
Error Bound ✓
Subcategory Bucket
Daily Volumes Total 0.000543 0.250000 ✓

Overall summary

Error Bound ✓
Category Subcategory Bucket
Origin-Destination Flows Commute Departures per Hour By County nan 0.100000 NA
Auto Daily Volumes <10k daily 0.419706 0.500000 ✓
10-20k daily 0.236962 0.350000 ✓
20-40k daily 0.130518 0.250000 ✓
40-60k daily 0.122318 0.200000 ✓
60-80k daily 0.095294 0.150000 ✓
80-100k daily 0.084703 0.120000 ✓
>100k daily 0.110537 0.100000 ≈
Traffic Speeds Morning Peak Other roads nan 0.300000 NA
Evening Peak Other roads nan 0.300000 NA
Morning Peak Arterials nan 0.150000 NA
Evening Peak Arterials nan 0.150000 NA
Morning Peak Freeways nan 0.100000 NA
Evening Peak Freeways nan 0.100000 NA
Transit Regionwide Total Daily Trips nan 0.050000 NA
Daily Boardings 0.087515 0.050000
Daily Volumes <2000 daily 0.219205 1.000000 ✓
2000-5000 daily 0.244949 0.500000 ✓
5000-10000 daily 0.205924 0.300000 ✓
10000-20000 daily 0.172848 0.200000 ✓
>20000 daily 0.273966 0.150000
On demand auto Daily Volumes by Origin Tract 1000+ daily 0.023222 0.250000 ✓
Daily Volumes by Destination Tract 1000+ daily 0.030115 0.250000 ✓
Freight Daily Volumes Total 0.000543 0.250000 ✓

Additional Metrics

Mode split

This section reports on the total number of travel activities (linked trips) by their primary travel mode.
Total activities Percent
Mode
Biking 1003150 1.59
Carpool 4535292 7.19
Commercial 2092745 3.32
On demand auto 609238 0.97
Other travel mode 3974659 6.30
Private auto 37333597 59.18
Public transit 594222 0.94
Walking 12937553 20.51
Mode split, Table 1: Total travel activities by mode

Trip generation summaries

Avg trips per household Avg trips per person
Household size
1 3.88 3.88
2 7.79 3.90
3 10.13 3.38
4 11.37 2.84
5 plus 15.86 2.52
Trip summaries, Table 1: Average number of trips per person/household by household size
Total trips Percent
Purpose
Commercial 2132873 3.38
Eat 4955784 7.86
Home 20647834 32.73
Lodging 666085 1.06
Maintenance 3103094 4.92
Other activity type 985754 1.56
Recreation 4192556 6.65
Region departure 178414 0.28
School 573621 0.91
Shop 12841604 20.36
Social 8557832 13.57
Stage 136926 0.22
Work 4108079 6.51
Trip summaries, Table 2: Distribution of trip purpose

Trip distance/duration summaries

Biking

Carpool

On demand auto

Private auto

Public transit

Walking

Trip summaries, Figure 1: Distance/duration distributions by mode, trip purpose. For informational purposes only.

Notes

  • Trip distance and duration summaries are provided for informational purposes only.

Comute flows by county

Commute flows by county, Figure 1: Commute departures by hour vs CTPP broken out by county