Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
56 NCHRP Synthesis 38-10 Survey of High Speed WIM System Calibration Practices Background: Since their inception, the performance of weigh-in-motion (WIM) systems in effectively capturing truck weight data has been the focus of considerable investigation. Recently, the deployment of WIM systems has proliferated through initiatives such as the LTPP and the Commercial Vehicle Information Systems and Networks (CVISN) programs. Proper calibration is essential in achieving adequate WIM system performance and ensuring the quality of obtained data. This is becoming paramount in meeting the functional demands of public agencies and the trucking industry alike. Objective: The purpose of this Synthesis is to assemble state-of-the-practice information on the actual methodologies State agencies use in evaluating and calibrating their high speed WIM systems as well as monitoring the calibration of these systems over time. The survey questionnaire that follows is intended to collect this information. It is addressed to the manager of State agencies in charge of WIM used either for data collection or enforcement. We expect that some states will submit two surveys one for WIM used in traffic data collection and one for WIM used in enforcement screening. Definition of terms: High Speed refers to highway speeds (i.e., up to 80 mph) and as such includes WIM systems installed on mainline and utilized for data collection or enforcement screening, (i.e., it excludes enforcement screening WIM systems installed on approach ramps to truck inspection stations). WIM System refers to one controller, its computer and associated electronics, and all roadway sensors for all lanes for which traffic data is being processed by the controller and at least one lane is instrumented with weigh-in-motion sensors. WIM Lane refers to any lane which is instrumented with weigh-in-motion sensors. Type I and Type II WIM refer to the definitions given by ASTM E1318-02. Type I systems weigh individually the right and left-hand side axles, while Type II systems weigh whole axles. ASTM E1318-02 accuracy tolerances are more stringent for Type I than for Type II systems. Type I systems are typically equipped with bending plates, load cell plates or quartz sensors. Type II systems are typically equipped with 6´ or 12´piezoelectric sensors in various configurations. Site Assessment encompasses on-site activities preceding either an on-site evaluation or calibration to ensure that the WIM system is operational, the sensors have no visible problems and the pavement shows no signs of significant distress. APPENDIX B Survey Questionnaire
57 Evaluation/Validation refers to the on-site activities related to ascertaining compliance of WIM systems to error tolerances. It involves test trucks or samples of trucks from the traffic stream. It includes on-site testing for initial system acceptance, routine checks for calibration maintenance, and conformance to warranty requirements. Calibration involves adjusting the systemâs constant by setting the mean error measurements to zero. Calibration data is typically obtained from test trucks or traffic stream trucks of known static weights. WIM Calibration Monitoring is a data analysis that typically involves comparisons of representative traffic stream values to known load trends, (e.g., the weight of steering axles of 5-axle semi-trailers varies within a fairly narrow range and their gross vehicle weight exhibits a distinct double-peak pattern). Auto-calibration is a mechanism built into WIM software effecting automatic calibration adjustments when certain measurements fall outside prescribed limits. INSTRUCTIONS: Fill in the survey starting below. In the questions you will be asked to type in or click on responses. Each time you click on the Next Page button your responses are automatically saved. You can change your responses by paging back using the Previous Page button and reentering a response. (NOTE: Do NOT use your web browser's back and forward arrow buttons.) You can exit the WebSurveyor website at any time and your responses will be saved, allowing you to return to it later. If you complete part of the survey and want someone else to complete another section, you can do so by forwarding the email with the link to them and they will be able to access your partially completed survey using the same UniqueID and password. NOTE: Once you click on the Submit Survey button at the end the survey, you can no longer edit nor see your responses. To avoid having difficulty paging forward and backward through he survey it is advisable that you clear your cache before you complete this survey. Your cache is the temporary internet files folder. In Windows Explorer go to Tools/Internet Options/General and then delete Temporary Internet files.
Estimated time to complete survey: 1 to 1.5 hours Part 1: PRIMARY RESPONDENT'S INFORMATION We assume that multiple parties will be contributing to this survey but only want the name and contact information for the primary state department/division/agency person responsible for completing this survey listed here. Name: Title: Agency: Unit/Department/Division: Mailing Address including city, state and zip: Phone (please include extension, if any): e-mail: 58
59 Is there another unit(department/division/agency) in your State managing high speed WIM systems used for a different purpose (i.e. , data collection versus enforcement)? No Yes If Yes, please provide a contact name and information (address, phone, email) for the other unit below. We will send them a separate survey to complete. Please comment below on whether your unit cooperates with that other unit and how: Part 2: DESCRIBE YOUR WIM PROGRAM 2.1 What are the WIM systems for which your unit is primarily responsible used for? Traffic Data Collection Only Enforcement Screening Only Traffic Data Collection and Enforcement Screening
2.2 Which types of WIM systems have been installed by/for your unit? Type I Type II Other (please specify) If you selected other, please specify: 2.3 Is auto-calibration typically utilized by your systems during routine data collection? No - It is not used in our systems Yes Additional comments: If Yes, for which system types? Check all that apply. Not Applicable - Do not use auto-calibration. Type I Type II Other (please specify) If you selected other, please specify: Additional comments: 60
61 Part 3: WIM SYSTEM CALIBRATION PRACTICES AND PROCEDURES 3.1 Is a post-installation system calibration always performed? Yes No (click on next page to skip to 3.4) Additional comments: 3.2 Who performs this post-installation calibration? Check all that apply. In-House Staff WIM Vendor Other contractor Other (please specify) If you selected other, please specify: Additional comments: 3.3 Is the post installation calibration procedure any different than the routine calibration? No Yes: highlight the major DIFFERENCES in comment field below Additional comments:
3.4 Which methods do you use for the evaluation/calibration of high speed WIM systems throughout their lives? Check all that apply. On-site evaluation/calibration using test trucks On-site evaluation/recalibration using traffic stream vehicles of known weights Calibration monitoring through quality control analysis of traffic stream data Other (please specify) If you selected other, please specify: Additional comments: 3.5 WIM On-Site Evaluation/Calibration Procedures Using Test Trucks NOTE: The majority of the questions under 3.5 relate to the general provisions of the ASTM Standard E1318-02 and the LTPP WIM System Calibration Protocol. They are intended to determine which parts of these standards your unit may be using. Do you perform on-site evaluation/calibration using test trucks? Yes No (click on next page to skip to 3.6) 62
63 In the series of questions under 3.5 please describe the procedure you use for the MOST COMMON WIM type in your unit (department/division/agency). What is the most common WIM type in your unit for which test trucks are used for calibration? Type I Type II Other (please specify) If you selected other, please specify: Additional comments: 3.5.1 Who conducts these on-site evaluation/calibration activities using test trucks? Check all that apply. In-House Staff Outsourcing to an external on call contractor Outsourcing to an external contractor that manages evaluation/calibration activities Additional Comments: If you are outsourcing WIM calibration, you may want to ask for the contractor's assistance in responding to the following questions. 3.5.2 What is the criterion you use to initiate test-truck WIM calibration? Check all that apply. It is routinely scheduled It is carried out only when calibration monitoring using traffic stream vehicles of known weight or traffic data indicates a calibration drift. Other (specify in Comments) If routinely scheduled, specify typical interval (months):
Additional comments: 3.5.3 Do you have procedures for conducting diagnostic tests to ensure proper operation of the WIM system prior to committing to a complete on-site evaluation and/or calibration? No Yes If Yes, how are these diagnostic tests conducted? Check all that apply. Not Applicable - Do not conduct diagnostic tests From the office by performing system diagnostics and/or data analyses At the site by performing system diagnostics and real-time monitoring Other (please specify) If you selected other, please specify: Additional comments: 3.5.4 Do you have procedures for inspecting the condition of the WIM sensors? No Yes If Yes, on which of the following do you perform a visual inspection? Check all that apply. Not Applicable - Do not have procedures for sensor inspection. Physical damage to sensor Proper levelling of sensors with pavement surface 64
65 Secure attachment of sensors to pavement surface and/or frame Other (please specify) If you selected other, please specify: Additional comments: 3.5.5 When conducting test-truck WIM calibrations, do you consider the pavement smoothness at the WIM site? No - Not Considered Considered only when system fails to meet accuracy tolerances. Yes, always considered. Additional comments: In cases where the pavement smoothness is considered which methods are used? Check all that apply. Not Applicable - Pavement smoothness not considered. Visual Inspection An inertial profilometer to obtain IRI An inertial profilometer to simulate straight-edge/pack test Other profile-based method Physical straight-edge/pack test Other (please specify) If you selected other, please specify: Additional comments:
3.5.6 In conducting WIM calibrations with test trucks, do you consider the structural condition (deflection) of the pavement supporting the WIM sensors? No Yes, please highlight method in Comments. Additional comments: 3.5.7 How are test trucks procured? Check all that apply. Agency owned Rented from trucking firm by Agency Rented from trucking firm by WIM vendor or other contractor Other (please specify) If you selected other, please specify: Additional comments: 3.5.8 How many test trucks are used by class or type? FHWA Class or Type Number FHWA Class or Type Number FHWA Class or Type Number FHWA Class or Type Number Additional comments ( If more than 4 types are used please indicate the type(s) and number(s) here): 66
67 3.5.9 Do you specify the suspension type of these test trucks? No Yes Additional comments: If Yes, which types are specified? Check all that apply. Not Applicable - Types not specified. Air Leaf Spring Representative of the suspension types at the WIM site Other (please specify) If you selected other, please specify: Additional comments: 3.5.10 What is your test truck loading criteria? Loaded to 90% to 100% of their legal load limit Loaded to reflect the local truck population loadings at the WIM site Other (please specify) If you selected other, please specify: Additional comments: 3.5.11 Please provide the following details on static weighing in conjunction with WIM calibration using test trucks. Do you require that static scales be certified?
No Yes Additional comments: Which types of static scales do you use? Check all that apply. Fixed Portable Other (please specify) If you selected other, please specify: Which static weights are obtained? Check all that apply. Individual wheel/wheel sets for left and right wheel path Individual axles Axle groups Other (please specify) If you selected other, please specify: How many times is each static weight measured? Additional comments regarding static weight practices: 3.5.12 Are the axle spacings for each test truck measured? No 68
69 Yes Additional comments: 3.5.13 Are the test truck speeds measured as they cross the sensors? No Yes, at least for the first few passes Yes, for every pass Additional comments: 3.5.14 How is test truck speed measured? Not Applicable - Test truck speeds are neither measured nor their WIM speeds verified. By using a calibrated radar speed meter. Speed itself not measured, but WIM speed is verified by comparing WIM axle spacings to the measured axle spacings. By another method. Please specify in comment field below. Additional comments: 3.5.15 At what speeds do the test trucks run? Single speed set at posted speed limit Single speed set at median speed of truck traffic stream Multiple speeds selected randomly by the driver Multiple speeds selected by agency within a range (specify range in Comments) Other (specify in Comments) Additional comments:
3.5.16 Is there a minimum number of test truck runs required at each speed? No Yes If Yes, please specify the minimum number of runs: Number of runs for each speed. Additional comments: 3.5.17 Are the test truck drivers given specific instructions as to the desired lane and speed for each run? No No, but they are advised to alter lanes and speeds within the ranges specified above. Yes Additional comments: If Yes, by what means are the instructions given? Check all that apply. Not Applicable CB radios or cell phones Check-off lists Other (please specify) 70
71 If you selected other, please specify: Additional comments: 3.5.18 Is the system auto-calibration turned off during test truck runs? Not Applicable - Auto-calibration not available. No Yes Do Not Know Additional comments: 3.5.19 How is the test truck data being recorded during WIM calibration testing? Manual real-time recording of test truck WIM record numbers and WIM measurements. Electronic (computer printout or file) real-time recording of test truck WIM record numbers and WIM measurements. Real-time test truck WIM record numbers recorded only, while WIM measurements are retrieved later from system's datafiles for off-site processing. Other (please specify) If you selected other, please specify: Additional comments: If test truck data is manually recorded, what method is used? Not Applicable - Do not manually record. Pencil/Paper Direct Computer Keyboard Entry Other (please specify)
If you selected other, please specify: Additional comments: 3.5.20 When performing on-site calibration using test trucks are the WIM error computations performed on-site? Never Yes, always Yes, only if it is evident that additional sampling of traffic steam trucks may be needed. Additional comments: 3.5.21 During on-site calibration using test trucks how are the WIM error computations carried out? Manually, with hand-held calculator Using a spreadsheet or other analysis program supplied by a vendor Using a spreadsheet or other analysis program developed by your Agency Other (please specify) If you selected other, please specify: Additional comments: 3.5.22 During on-site calibration using test trucks what error formula is used? The percent difference between WIM measurement and the corresponding static value. Other (please specify) If you selected other, please specify: 72
73 Additional comments: 3.5.23 For which of the following measurements are WIM errors computed during on-site calibration using test trucks? Check all that apply. Speed Wheel load and/or axle load Tandem axle load Gross vehicle weight Axle spacing Overall vehicle length Other (please specify) If you selected other, please specify: Additional comments: 3.5.24 Are test trucks ever run for the sole purpose of determining WIM system accuracy tolerance pass/fail (e.g. new site acceptance, warranty, etc.)? No, calibration (or recalibration) is always done in conjunction with accuracy validation Yes, but under a fail situation vendor/contractor may use test truck data to recalibrate system Yes, but under a fail situation vendor/contractor must recalibrate using own trucks Other (please specify) If you selected other, please specify: Additional comments: 3.5.25 During on-site calibration using test trucks, what method is used to compute the calibration factors? By setting the mean of the axle load arithmetic errors to zero
By setting the mean error of the GVW to zero By combining the two methods above By setting the slope of the WIM versus static axle load measurements to zero Do Not Know ( It is incorporated in the error computation spreadsheet) Other (please specify) If you selected other, please specify: Additional comments: 3.5.26 During on-site evaluation using test trucks do you compute calibration factors for two or more speed points? Yes, our systems provide for two or more speed point factor entries and we do compute factors for each by analyzing data by speed. No, although our systems provide for two or more speed point factor entries a single factor is computed and used for all speed points. No, our systems provide for only a single factor. Other (please specify) If you selected other, please specify: Additional comments: 3.5.27 What remedial action is taken for WIM systems that fail to meet accuracy tolerances during test truck testing? System is summarily abandoned or removed A site evaluation is undertaken to ascertain roughness and structural condition, as described earlier under 3.5.5 and 3.5.6 System remains in use, but the data is used only for specific purposes Other (please specify) If you selected other, please specify: 74
75 Additional comments: What is the use of the data being generated by WIM systems that fail to meet accuracy tolerances? Not Applicable- sites evaluated and/or abandoned or removed Count/Classification Applications requiring only low quality weight estimates Other (please specify) If you selected other, please specify: Additional comments: 3.6 WIM On-Site Evaluation/Calibration Using Traffic Stream Trucks of Known Weight NOTE: In this section we are referring to on-site evaluation/ calibration by sampling trucks from the traffic stream for which you are able to obtain static weights. Do you perform on-site evaluation/calibration using traffic stream trucks of known weights? Yes No (click on next page to skip to 3.7) In the series of questions under 3.6 please describe the procedure you use for the MOST COMMON WIM type in your unit(department/division/agency). What is the most common WIM type in your unit for which traffic stream trucks of known weight are used for calibration? Type I Type II
Other (please specify) If you selected other, please specify: 3.6.1 Who conducts these on-site evaluation/calibration activities using traffic stream trucks of known weight? Check all that apply. In-House Staff Outsourcing to an external on-call contractor Outsourcing to an external contractor that manages evaluation/calibration activities. Additional Comments: If you are outsourcing WIM calibration, you may want to ask for the contractor's assistance in responding to the following questions. 3.6.2 What is the criterion you use to initiate WIM calibration using traffic stream trucks of known weight? Check all that apply. It is routinely scheduled It is carried out only when calibration monitoring using traffic data indicates a calibration drift. Other (specify in Comments) If routinely scheduled, specify typical interval (months): Additional comments: 76
77 3.6.3 How do you select the number of traffic stream trucks of known weight to be included in the sample? A fixed number of trucks is selected. All the trucks in a given time interval are selected. Some of the trucks in a given time interval are selected. Other (specify in Comments) If a fixed number of trucks are selected, specify the number. If all of the trucks in a given time interval are selected, specify the time interval (in hours). If some of the trucks in a given time interval are selected, specify the number and interval: Number of Trucks Time Interval (in hours) Additional comments: 3.6.4 What are the criteria used for selecting the type of traffic stream trucks of known weight to include in the sample? No particular criteria, i.e. sample is random Selecting specific truck classes, regardless of speed. Specify classes in Comments. Selecting specific truck classes by speed. Specify classes and speeds in Comments. Other (please specify) If you selected other, please specify: Additional comments:
3.6.5 How is the static weight of these traffic stream trucks obtained? Using portable scales Utilizing a nearby static enforcement facility. Other (please specify) If you selected other, please specify: Additional comments: If using a weight enforcement facility, how is the static weight of the traffic stream trucks recorded? Not Applicable - Weight enforcement facility not used. Automatically Manually Additional comments: 3.6.6 Do you measure the axle spacing for these traffic stream trucks? No Yes Other (please specify) If you selected other, please specify: Additional comments: If Yes, how do you measure the axle spacing? Not Applicable - Axle spacing not measured. 78
79 Manually Electronically Other (please specify) If you selected other, please specify: Additional comments: 3.6.7 Is the system auto-calibration turned off during traffic stream truck runs? Not Applicable - Auto-calibration not available. No Yes Do Not Know. Additional comments: 3.6.8 How is the WIM data of the sampled traffic stream trucks of known weight recorded? Manual real-time recording of test truck WIM record numbers and WIM measurements. Electronic (printout or file) real-time recording of test truck WIM record numbers and WIM measurements. Real-time test truck WIM record numbers recording only, while WIM measurements are retrieved later from system's data files for off-site processing. Other (please specify) If you selected other, please specify: Additional comments: 3.6.9 Are the on-site calibration using traffic stream trucks of known weight WIM error computations performed on-site?
Never Yes, always Yes, only if it is evident that additional sampling of traffic stream trucks may be needed Additional comments: 3.6.10 During on-site calibration using traffic stream trucks of known weight how are the WIM error computations carried out? Manually, with hand-held calculator Using a spreadsheet or other analysis program supplied by a vendor Using a spreadsheet or other analysis program developed by your Agency Other (please specify) If you selected other, please specify: Additional comments: 3.6.11 For which of the following measurements are WIM errors computed? Check all that apply. Speed Wheel load and/or axle load Tandem axle load Gross vehicle weight Axle spacing Overall vehicle length Other (please specify) If you selected other, please specify: Additional comments: 80
81 3.6.12 Are traffic stream trucks of known weight ever sampled for the sole purpose of determining WIM system accuracy tolerance pass/fail (e.g. new site acceptance, warranty, etc.)? No, calibration (or recalibration) is always done in conjunction with accuracy validation Yes, but when "fail" vendor/contractor may use test truck data to recalibrate system Yes, but when "fail" vendor/contractor must recalibrate using own trucks Other (please specify) If you selected other, please specify: Additional comments: 3.6.13 During on-site calibration using traffic stream trucks of known weight, what method is used to compute the calibration factors? By setting the mean of the axle load arithmetic errors to zero By setting the mean error of the GVW to zero By combining the two methods above By setting the slope of the WIM versus static axle load measurements to zero Do Not Know ( It is incorporated in the error computation spreadsheet) Other (please specify) If you selected other, please specify: Additional comments: 3.6.14 During on-site calibration using traffic stream trucks of known weight do you compute calibration factors for two or more speed points? Yes, our systems provide for two or more speed point factor entries and we do compute factors for each by analyzing data by speed.
No, although our systems provide for two or more speed point factor entries a single factor is computed and used for all speed points. No, our systems provide for only a single factor. Other (please specify) If you selected other, please specify: Additional comments: 3.6.15 What remedial action is taken for WIM systems that fail to meet accuracy tolerances during traffic stream truck evaluation? System is summarily abandoned or removed A site evaluation is undertaken to ascertain roughness and structural condition, as described in 3.5.5 and 3.5.6 On-site evaluation using test trucks is undertaken, as described in 3.5 System remains in use, but the data is used only for specific purposes Other (please specify) If you selected other, please specify: Additional comments: What is data from systems that remain in use but fail to meet accuracy tolerances used for? Not Applicable-Sites evaluated and/or abandoned or removed. Count/Classification Applications requiring only low quality weight estimates Other (please specify) If you selected other, please specify: 82
83 Additional comments: 3.7 WIM Calibration Monitoring Using Traffic Stream WIM Data Do you use WIM calibration monitoring using traffic stream WIM data to monitor your WIM systems? Yes No (click on next page to skip to Part 4) Additional comments: 3.7.1 Who conducts WIM calibration monitoring using traffic stream WIM data? Check all that apply. In-House Staff Outsourcing to an external on-call contractor Outsourcing to an external contractor that manages evaluation/calibration activities. Additional comments: If you are outsourcing WIM calibration, you may want to ask for the contractor's assistance in responding to the following questions. 3.7.2 Typically, how often are your systems' data files downloaded? Daily Weekly Monthly Other (please specify)
If you selected other, please specify: Additional comments: 3.7.3 How are your systems' data files downloaded? Manually - utilizing communications software or via the internet Automatically - utilizing proprietary auto-polling software Other (please specify) If you selected other, please specify: Additional comments: 3.7.4 How often do you perform checks of the WIM data? Daily Weekly Monthly Other (please specify) If you selected other, please specify: Additional comments: 3.7.5 How is your WIM data analysis performed? Manually, using judgment to detect departure of known traffic stream properties from their expected ranges Automatically, using software to perform these tests (e.g. commercial or in-house developed software) Other (please specify) 84
85 If you selected other, please specify: Additional comments: If your data analysis is performed automatically using software, when is it carried out? Not Applicable - Not automatic As an integral part of the download As a separate step Additional comments: 3.7.6 In your opinion, do the analyses of your WIM data identify most system operational problems and atypical traffic characteristics? No Yes Additional comments: If Yes, which types of system operational problems and/or atypical traffic characteristics are identified? Check all that apply. Not Applicable Missing or atypical vehicle counts by hour Atypical class counts and/or distributions Large number or percentage of unclassified vehicles Large number of system error flags (e.g. loop not triggered) Large number of vehicle record flags (e.g. possible axle or wheel weighing errors) Other (please specify)
If you selected other, please specify: Additional comments: 3.7.7 Which traffic stream vehicle types are utilized for calibration monitoring? Check all that apply. All FHWA Class 9's 3S2 Only Other (please specify) If you selected other, please specify: Additional comments: 3.7.8 Which characteristics are monitored through WIM calibration monitoring using traffic stream WIM data? Check all that apply. GVW average by speed GVW standard deviations GVW graph and/or listing of empty vs. loaded distributions Other GVW property Steering axle weight average Steering axle weight standard deviations Steering axle left/right wheel weights Other steering axle property Tractor tandem axle spacing Other axle spacing property Overall vehicle lengths vs. overall axle spacing Other (please specify) If you selected other, please specify: 86
87 Additional comments: 3.7.9 If the monitoring of traffic stream characteristics indicates a system is experiencing calibration "drift" what action is taken? No action is taken. Calibration factors are adjusted from the office by remote access On-site evaluation/calibration as described earlier is triggered Other (please specify) If you selected other, please specify: Additional comments: 3.7.10 If calibration factors are adjusted from the office, do you check the effect on the traffic characteristics described in 3.7.8? Those characteristics included: (GVW Average, GVW Average by speed, Steering axle weight average, etc.). Not Applicable - Calibration factors NOT adjusted from office No, Never Yes, Always Sometimes. Please note in Comments field when it is checked. Additional comments: 3.7.11 Do you keep records of WIM calibration factor adjustments? No Yes Additional comments: If Yes, how are records kept?
Not Applicable - Records not kept. Automatically through the WIM system software Manually Additional comments: Part 4: YOUR OPINION 4.1 In your opinion, are your Type I traffic data systems generating data of adequate quality to meet the requirements for the intended purposes? Not Applicable - Not responsible for any Type I systems used for traffic data More than adequate quality Generally adequate quality Of marginal or borderline quality Inadequate quality Very inadequate quality - please give main reasons in Comments. No Opinion Additional comments: 4.2 In your opinion, are your Type I main line enforcement screening and/or sorting systems effective? Not applicable - Not responsible for any Type I systems used for enforcement screening and/or sorting More than effective Generally effective Of marginal or borderline effectiveness Ineffective Very ineffective - Please give main reasons in Comments. No opinion Additional comments: 88
89 4.3 In your opinion, are your Type II traffic data systems generating data of adequate quality to meet the requirements for the intended purposes? Not Applicable - Not responsible for any Type II systems used for traffic data More than adequate quality Generally adequate quality Of marginal or borderline quality Inadequate quality Very inadequate quality - please give main reasons in Comments. No Opinion Additional comments: 4.4 In your opinion, are your Type II main line enforcement screening and/or sorting systems effective? Not applicable - Not responsible for any Type II systems used for enforcement screening and/or sorting More than effective Generally effective Of marginal or borderline effectiveness Ineffective Very ineffective - Please give main reasons in Comments. No opinion Additional comments: 4.5 In your opinion, given additional resources for high speed WIM traffic data collection and enforcement, which of the following would your unit consider? Check all that apply. Install additional WIM systems Install newer and better technology WIM systems to replace current ones
Perform more intensive system diagnostics and calibration monitoring Perform more on-site system calibrations Additional comments: 4.6 In your opinion, what is the main factor hindering proper WIM calibration and how could it be solved? 4.7 In your opinion, what are the most urgent WIM technical needs at present and what studies need to be conducted to address them? Please provide any additional comments you may want to share about high speed WIM calibration. 90
91 Part 5: INVENTORY OF WIM SYSTEMS This last part of the questionnaire is optional. It is an inventory of WIM systems in your state. Do you want to complete it? Yes No (click next page to skip to end of survey) INVENTORY OF TYPE I WIM SYSTEMS 5.1 Approximately how many Type I WIM systems are currently in use by your unit for the following purposes: Please put in a "0" if you have no systems that fall into a category or you are not responsible for those systems. Dual Use - A Single WIM System Used for Both Traffic Data Collection AND Enforcement Screening Approximate number of Type I WIM Systems Approximate Number of Type I WIM Lanes Sensor Type(s) Single Use - Traffic Data Collection ONLY Approximate Number of Type I WIM Systems Approximate Number of Type I WIM Lanes Sensor Type(s) Single Use - Enforcement Screening ONLY
Approximate Number of Type I WIM Systems Approximate Number of Type I WIM Lanes Sensor Type(s) INVENTORY OF TYPE II WIM SYSTEMS 5.2 Approximately how many Type II WIM systems are currently in use by your unit for the following purposes: Please put in a "0" if you have no systems that fall into a category or you are not responsible for those systems. Dual Use - A Single WIM System Used for Both Traffic Data Collection AND Enforcement Screening Approximate Number of Type II WIM Systems Approximate Number of Type II WIM Lanes Sensor Type(s) Single Use - Traffic Data Collection ONLY Approximate Number of Type II WIM Systems Approximate Number of Type II WIM Lanes Sensor Type(s) Single Use - Enforcement Screening ONLY Approximate Number of Type II WIM Systems Approximate Number of Type II WIM Lanes Sensor Type(s) Thank you again for your time and effort in completing this survey. 92
