Wrapping up the CTPPWrapping up the CTPP

What you should knowWhat you should know Ed J. Christopher

FHWA Resource Center near Chicago

19900 Governors DriveOlympia Fields, IL 60461

708-283-3534

edc@edthefed.com

April 26, 2005April 26, 2005

TodayToday

Run Through CTPPRun Through CTPP

Cover Some CTPP/Census Data Cover Some CTPP/Census Data IssuesIssues

WhatWhat is the CTPP? is the CTPP?

The Census Transportation The Census Transportation Planning Package is a set of special Planning Package is a set of special

tabulations from the long form of tabulations from the long form of the decennial census designed by the decennial census designed by

transportation planners for transportation planners for transportation plannerstransportation planners

It summarizes the dataIt summarizes the data

At ResidenceAt ResidenceAt WorkplaceAt Workplace

Flows between Flows between Home and WorkHome and Work

CTPP Main ProductsCTPP Main Products

Tabulations Tabulations at Residenceat Residence

Tabulations Tabulations at Workplaceat Workplace

Flows between Flows between HomeHome and and WorkWork

Part 1Part 1 Part 2Part 2 Part 3Part 3

The CATThe CATCTPP Access ToolCTPP Access Tool

How is it packaged?How is it packaged?

ASCII TooASCII Too

Part 1 -- Residence Data Part 1 -- Residence Data (Done)(Done)

BTS has Final ASCII version on TranStatsBTS has Final ASCII version on TranStats

Final CAT Files distributed to MPOs / statesFinal CAT Files distributed to MPOs / states

Part 2—Work Place Data Part 2—Work Place Data (Done)(Done)Final ASCII on BTS TranStatsFinal ASCII on BTS TranStats

Final CAT @ BTS BookstoreFinal CAT @ BTS Bookstore

Part 3— Flow DataPart 3— Flow DataFinal ASCII Final ASCII (Done)(Done)

Coming Soon!!!!!Coming Soon!!!!!

When was it released?When was it released?

Where do I get the Where do I get the “FREE” “FREE” CTPP ASCII Files?CTPP ASCII Files?

http://www.transtats.bts.gov/http://www.transtats.bts.gov/

Where do I get the Where do I get the “FREE”“FREE” CTPP with Software?CTPP with Software?

https://www.bts.gov/pdc/https://www.bts.gov/pdc/

Install New (Part 3) Viewer SoftwareInstall New (Part 3) Viewer Software

Rounding and ThresholdsRounding and Thresholds

Workplace GeocodingWorkplace Geocoding

Worker CountsWorker Counts

Top CodingTop Coding

CTPP Data IssuesCTPP Data Issues

Disclosure Review BoardDisclosure Review Board

CTPP 2000 Post DRB

Part 1: at Residence (121 Tables) All Tables Rounded Zero = 0 1 through 7 = 4 8 though = Nearest Multiple of “5”

Part 2: at Workplace (68 Tables) All Tables Rounded

Part 3: Worker Flows (14 Tables) All Tables Rounded Some Tables with Thresholds

Mode to Work

Circa 1990For 2000

(ROUNDED)

Total 352 350 (not 355!)

Drive Alone 212 210

Carpool 46 45

Transit 59 60

Walk 33 35

Bike 2 4

Example of RoundingExample of Rounding

True Total 354True Total 354

Using the CTPP, 10 + 10 + 10 + 10 = ?Using the CTPP, 10 + 10 + 10 + 10 = ?

Pop Quiz!Pop Quiz!

a)a) 30 30 c)c) 35 35 e)e) 40 40b)b) 45 45 d)d) 50 50 f)f) Any of the Any of the

Above Above

Here's a real life example using the CTPP Part 2 data. Let's Here's a real life example using the CTPP Part 2 data. Let's say my boss asks as simple question: "How many transit say my boss asks as simple question: "How many transit commuters are at work in the Bay Area?" Using the Part 2 commuters are at work in the Bay Area?" Using the Part 2 data, I am able to provide my boss 15 different answers!data, I am able to provide my boss 15 different answers!

Chuck Purvis, MTCChuck Purvis, MTC

Total SOV Carpool Bus Rail Other Home Row TotL11423 49,275 12,200 3,915 6,410 24,580 2,160 10 49,275L11428 29,365 8,315 2,340 4,210 12,780 1,715 4 29,364L11446 15,035 3,705 1,240 2,430 7,010 640 15 15,040L11448 5,200 3,115 550 570 745 150 65 5,195L11449 25,655 7,240 2,120 2,775 12,325 1,195 0 25,655L12427 920 410 155 65 85 95 105 915L12428 9,610 3,025 835 1,660 3,535 555 0 9,610L12446 22,115 4,925 1,770 4,595 9,915 905 0 22,110L12449 67,795 14,565 4,820 8,035 36,950 3,420 0 67,790

Rest 124,955 34,255 10,324 17,410 57,165 5,460 328 124,942

349,896

Col Tot 349,925 91,755 28,069 48,160 165,090 16,295 527

Chicago CBD Chicago CBD --CTPP 2000 DataCTPP 2000 Data

SF3 CTPP SF3 CTPP SF3 CTPP

1.01 2,021 2020 1,850 1845 1,697 16951.02 1,231 1230 1,099 1094 1,062 10602.01 3,614 3615 2,899 2905 2,573 25752.03 243 245 191 190 129 1302.04 2,036 2035 1,605 1605 1,485 14853.01 4,084 4085 3,065 3065 2,686 26853.02 3,342 3340 2,352 2350 2,194 21953.03 1,766 1765 1,373 1370 1,074 1075

24.18 2,296 2295 2,134 2135 1,758 176024.19 2,207 2205 2,072 2070 1,831 183024.2 4,088 4090 3,747 3750 2,955 2955

24.21 2,246 2245 2,133 2130 1,786 178524.22 3,045 3045 2,725 2725 2,122 212024.23 3,116 3115 2,925 2930 2,489 249024.24 1,889 1890 1,757 1754 1,416 1415

433,064 433,080 383,508 383,409 324,475 324,4300.004% -0.026% -0.014%

Drove aloneCar, truck, vanTotal

Mode to Work for Travis County Residents

Tract

1.1. Obtain your "regional control totals" from the Obtain your "regional control totals" from the most geographically aggregate summary levelsmost geographically aggregate summary levels

2.2. Avoid aggregating (summing together) your Avoid aggregating (summing together) your geographiesgeographies

3.3. Avoid aggregating categoriesAvoid aggregating categories

4.4. Sum as few categories as possibleSum as few categories as possible

5.5. Adjust (de-round, un-round) as you see fit. SF3 Adjust (de-round, un-round) as you see fit. SF3 or PUMS can provide control totals to adjust or PUMS can provide control totals to adjust the CTPP Part 1 data.the CTPP Part 1 data.

6.6. Develop a sense of humor. Develop a sense of humor.

Rounding TipsRounding Tips

So is it "close enough for government work?"So is it "close enough for government work?"

Odd ModesOdd Modes

Linn County, Cedar Rapids IowaLinn County, Cedar Rapids Iowa

Odd ModesOdd Modes

Linn County, Cedar Rapids IowaLinn County, Cedar Rapids Iowa

ThresholdsThresholds

CTPP 2000 Post DRB

Part 1: at Residence (121 Tables) All Tables Rounded Zero = 0 1 through 7 = 4 8 though = Nearest Multiple of “5”

Part 2: at Workplace (68 Tables) All Tables Rounded

Part 3: Worker Flows (14 Tables) All Tables Rounded Some Tables with Thresholds

Table Content

1 Total Workers (1)

2 Vehicles Available (3--zero,one or two+) by Means of Transportation (7 modes)

3 Poverty Status (3 categories)

4 Minority Status (2--white non-hispanic and all others)

5 Household Income (8 classifications)

6 Means of Transportation (17 modes)

7 Household Income (4 classifications) by Means of Transportation (4 modes)

8Mean Travel Time by Means of Transportation to Work (7 modes) and Time

Leaving Home for Work (2--AM peak and all other times)

9Median Travel Time by Means of Transportation to Work (7 modes) and Time

Leaving Home for Work (2 groupings)

10 Aggregate Number of Vehicles by Time Leaving Home for Work (2, see table 8)

11 Number of Workers per Vehicle by Time Leaving Home for Work (2, see table 8)

12 Aggregate Number of Carpools by Time Leaving Home for Work (2, see table 8)

13 Number of Workers per Carpool by Time Leaving Home for Work (2, see table 8)

14Aggregate Travel Time by Means of transportation to work (7 modes) and Time

Leaving Home for Work (2, see table 8)

Part 3: Worker Flow Tables

No record No record thresholdthreshold

Must have 3 Must have 3

unweighted unweighted

recordsrecords

Intra-Bay Area, CTPP 2000, Part 3 AnalysisTable 3-1 Table 3-6

No Threshold w/ Thresholds

County-to-County 3,258,465 Loss 3,258,465 Loss

Place-to-Place 3,257,152 0.0% 3,221,359 -1.1%

Tract-to-Tract 3,209,952 -1.5% 2,154,754 -33.9%

Zone-to-Zone 3,143,432 -3.5% 937,749 -71.2%

DRB Impact on Part 3DRB Impact on Part 3

Special Thanks to Chuck Purvis, MTC Special Thanks to Chuck Purvis, MTC For this Analysis For this Analysis

Workplace GeocodingWorkplace Geocoding

Workplace GeocodingWorkplace Geocoding

Workplace Geocoding IssuesWorkplace Geocoding Issues

Automatic Geocoding (75%)Automatic Geocoding (75%)

Standard Allocation (25%)Standard Allocation (25%)

Industry ImprovementsIndustry ImprovementsTIGER Improvements (TAZ Definition)TIGER Improvements (TAZ Definition)

Work-up Clean-upWork-up Clean-upExtended allocation 10% (ala Lemoges)Extended allocation 10% (ala Lemoges)

http://www.trbcensus.com/articles/ctppworkers.pdfhttp://www.trbcensus.com/articles/ctppworkers.pdf

Workers at Work Counts vs. Workers at Work Counts vs. Other Employment SourcesOther Employment Sources

Total jobs are HIGHER than Census 2000 worker Total jobs are HIGHER than Census 2000 worker counts while CTPP Part 3 is Lower yet! counts while CTPP Part 3 is Lower yet! (Rounding)(Rounding)

CTPP uses NAICS, others may use SICCTPP uses NAICS, others may use SIC

Multi-site businesses and job types not reported Multi-site businesses and job types not reported consistentlyconsistently

Census 2000 employment estimates vs CPSCensus 2000 employment estimates vs CPS

Extended Allocation for CTPP small areasExtended Allocation for CTPP small areas

Top Coding of Travel TimeTop Coding of Travel Time

The top coding of travel time changed The top coding of travel time changed between 1990 and 2000. In 1990, the between 1990 and 2000. In 1990, the data field for travel time was limited to data field for travel time was limited to 2 digits thereby restricting travel time 2 digits thereby restricting travel time to a maximum of 99 minutes. In 2000, to a maximum of 99 minutes. In 2000, the field was 3 digits with a top coding the field was 3 digits with a top coding of 200 minutes.of 200 minutes.

Top CodingTop Coding

When I get my CTPP data what should I do?When I get my CTPP data what should I do?

Examine the dataExamine the data for your area as soon as for your area as soon as possiblepossible

Check its reasonablenessCheck its reasonablenessDoes it make sense?Does it make sense?Are people working where they should be?Are people working where they should be?Do the tables add up?Do the tables add up?

Report all data issues to Nanda Srinivasan, FHWA, Report all data issues to Nanda Srinivasan, FHWA, (Phone 202-366-5021, email (Phone 202-366-5021, email

nanda.srinivasan@fhwa.dot.gov)nanda.srinivasan@fhwa.dot.gov)

Stay ConnectedStay Connected

Are You on the CTPP-News Listserve?

Have You Seen our Newsletter (the Status Report)?

http://www.dot.gov/ctpphttp://www.dot.gov/ctpp

http://www.TRBcensus.comhttp://www.TRBcensus.com

202-366-5000202-366-5000

When Mining Your Census DataWhen Mining Your Census DataKeep us in MindKeep us in Mind

Let Us Know What You Have DoneLet Us Know What You Have DoneWe Are Always Interested We Are Always Interested

Want to…Want to…Show Off Your Work?Show Off Your Work?Gain National Gain National Exposure?Exposure?Meet Other Data Users?Meet Other Data Users?Tour Washington DC?Tour Washington DC?

Sound Exciting?Sound Exciting?

TRB Urban Data and Information Systems CommitteeTRB Urban Data and Information Systems Committee

Ed Christopher-Chair (708-283-3534)Ed Christopher-Chair (708-283-3534)

Now let’s head off to the races with our Now let’s head off to the races with our latest CTPPslatest CTPPs