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Potential Use of Archived Intelligent Transportation Systems Data for Government Reporting |
The results of comparing the traditional and ITS data dictionaries are displayed in Table 2.1. Overall, it may be observed that the current ITS data dictionaries have the potential to supply only a portion of the data required by government reporting systems. The primary reason for this is that the ITS data dictionaries do not contain all the data relevant to government reporting systems. Inconsistencies in data definitions (as expressed in the "Near Matches" column of Table 2.1) are a secondary reason for the inability of ITS to supply data to government reporting systems. Detailed analyses of how ITS sources can supply data to individual government reporting systems are presented in Tables A.1 to A.10, shown in Appendix A.
| Government Reporting System | No. Data Elements | Comparison to ITS Data Dictionaries | |
|---|---|---|---|
| Direct Matches | Near Matches | ||
| Highway Performance Monitoring System | 98 | 20 | 9 |
| Traffic Monitoring Guide | 45(1) | 8 | 14 |
| Highway Safety Information System | 233 | 29 | 33 |
| National Bridge Inventory | 116 | 2 | 8 |
| National Transit Database | 1,105 | 0 | 48(2) |
| Fatality Analysis Reporting System | 151 | 18 | 32 |
| General Estimates System | 79(3) | 13 | 10 |
| Motor Carrier Management Information System (Crash Data) | 51 | 23 | 16 |
| National Governors' Association Truck Crash Data | 37 | 14 | 27 |
| Hazardous Materials Incident Reporting System | 278 | 39 | 19 |
| Grade Crossing Inventory System | 134 | 5 | 4 |
| Totals | 2,327 | 171 | 220 |
1 Non-repeating fields
2 Crash-related data only
3 Additional elements beyond those common with FARS
The Highway Performance Monitoring System (HPMS) was developed in 1978 as a national highway transportation system database. It includes limited data on all public roads, more detailed data for a sample of the arterial and collector functional systems, and certain summary information for urbanized, small urban and rural areas. HPMS replaced numerous uncoordinated annual State data reports as well as biennial special studies conducted by each State. These special studies had been conducted to support a 1965 congressional requirement that a report on the Nation's highway needs be submitted to Congress every two years.
A major purpose of HPMS is to provide data that reflect the extent, condition, performance, use, and operating characteristics of the Nation's highways. These data are the source of a large portion of information published in the annual Highway Statistics Series and other FHWA publications. HPMS data form the basis of the analyses that support the biennial Condition and Performance Reports to Congress. These data are also used for assessing highway system performance under FHWA's strategic planning process and for apportioning Federal-aid funds under TEA-21. In addition, HPMS serves needs of the States, MPOs and local government and other customers in assessing highway condition, performance, air quality trends, and future investment requirements.
HPMS contains data on individual highway segments. The HPMS Universe covers all open-to-traffic public highway segments and contains 46 data elements. The HPMS Sample is a subset of the Universe and contains an additional 46 data elements (98 total). Data relate to the section's location, geometric features, traffic level, and pavement condition. The HPMS Sample is used in this analysis.
Approximately 30 percent of the HPMS data elements can be traced to ITS data sources (Table A.1). The TMDD is the most relevant ITS data source for HPMS.
Beginning with statewide highway planning surveys of the 1930s, the collection of information on traffic volumes, vehicle types, and truck weights has become a significant portion of the work of highway planning programs in terms of both cost and personnel. Manuals and guides have been issued describing data collection procedures for each type of activity. In the past, each traffic data collection activity was approached as a unique endeavor. Decisions regarding the degree to which each activity should be pursued (for example, number of monitoring sites, duration of monitoring, time or season of year for data collection) have generally been determined by available funding, perceived need for the data, and the size of previous data-gathering efforts rather than by a statistical analysis of what monitoring is necessary.
The Traffic Monitoring Guide (TMG) provides guidance for improving traffic counting, vehicle classification, and truck weighing. Beyond simply providing ideas for updating these activities, it also provides statistical procedures that will allow the manager to determine how much monitoring is needed to achieve a desired precision level. It has three main objectives:
The TMG is structured as four record types:
Most of the matches found to ITS sources were for data in the Station record (Table A.2). Traffic volume is specified by the TMDD but a collection interval is not specified; the hourly level specified in the TMG can be developed only if the TMDD "link volume" is specified at an hour or less. Vehicle classification of the traffic stream and truck weight data are not found in the TMDD, P1512, or ATIS data dictionaries. The Architecture allows for these data types but only in a general way; it is unclear how the Architecture's specifications will be transferred to specific and employable data dictionaries.
FHWA has developed the Highway Safety Information System (HSIS) to meet the needs of safety analyses. HSIS uses data already being collected by nine participating states for the management of the highway system, for the study of highway safety. HSIS is a roadway-based system that provides quality data on a large number of accident, roadway, and traffic variables. The data are acquired annually from a select group of States, processed into a common computer format, documented, and prepared for analysis. The data can be used to analyze a large number of safety problems. They can range from the more basic "problem identification" issues to identify the size and extent of a safety problem to modeling efforts that attempt to predict future accidents from roadway characteristics and traffic factors.
Both the TMDD and P1512 Data Dictionary can supply some data for the HSIS (Table A.3).
The National Bridge Inventory (NBI) is a collection of over 600,000 bridges throughout the United States. NBI data are supplied by the States as required by the National Bridge Inspection Standards for bridges located on public roads. The database is maintained in a format prescribed by the Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation's Bridges.
Most of the data in the NBI relate to the physical condition of the bridge components, as measured during annual inspections. The current ITS data sources have little to do with this type of data, although a handful of background data items may be linked from the TMDD (Table A.4).
The National Transit Database (NTD) is the system through which the Federal Transit Administration (FTA) collects uniform data needed by the Secretary of Transportation to administer department programs. The data consist of selected financial and operating data that describe mass transportation characteristics. The legislative requirement for NTD is found in Title 49 U.S.C. 5335(a). The NTD reporting system evolved from the transit industry-initiated Project FARE (Uniform Financial Accounting and Reporting Elements). Both the private and public sectors have recognized the importance of timely and accurate data in assessing the continued progress of the nation's mass transportation systems.
The majority of the NTD deals with financial and fundamental operating characteristics (e.g., number of vehicles in service/maintained, revenue-miles) of a transit agency. Some very basic crash information is maintained, and these data can be linked to the TMDD and P1512 Data Dictionary in the same way that the other traditional crash databases are linked.
The Fatality Analysis Reporting System (FARS), which became operational in 1975, contains data on a census of fatal traffic crashes within the 50 states, the District of Columbia, and Puerto Rico. To be included in FARS, a crash must involve a motor vehicle traveling on a traffic way customarily open to the public, and must result in the death of an occupant of a vehicle or a non-motorist within 30 days of the crash. NHTSA has a cooperative agreement with an agency in each state's government to provide information on all qualifying fatal crashes in the state. These agreements are managed by Regional Contracting Officer's Technical Representatives located in the 10 NHTSA Regional Offices. Trained state employees, called "FARS Analysts," are responsible for gathering, translating, and transmitting their state's data to NCSA in a standard format. The number of analysts varies by state, depending on the number of fatal crashes and the ease of obtaining data.
As with HPMS, the TMDD provides many of the potential geometric feature data (Table A.5). Both the TMDD and P1512 Data Dictionary can be linked to several crash-related data items.
The General Estimates System (GES) data are obtained from a nationally representative probability sample selected from all police-reported crashes. The system began operation in 1988. To be eligible for the GES sample, a police accident report (PAR) must be completed for the crash, and the crash must involve at least one motor vehicle traveling on a traffic way and result in property damage, injury, or death. Although various sources suggest that about half the motor vehicle crashes in the country are not reported to police, the majority of these unreported crashes involve only minor property damage and no significant personal injury. By restricting attention to police-reported crashes, GES concentrates on those crashes of greatest concern to the highway safety community and the general public.
GES data collectors make weekly visits to approximately 410 police jurisdictions in 60 sites across the United States, where they randomly sample about 57,000 PARs per year. The collectors obtain copies of the PARs and send them to the National Automotive Sampling System (NASS) quality control centers for coding. No driver license, vehicle registration, medical information, or any other sensitive data are collected beyond the selected PAR entries, due to privacy reasons. GES includes most of the FARS data elements, but collects additional detail on crashes.
P1512 Data Dictionary is the primary source of the non-FARS data elements in GES (Table A.6).
The Motor Carrier Management Information System (MCMIS) is a computerized system whereby the Federal Motor Carrier Safety Administration (FMCSA) maintains a comprehensive record of the safety performance of the motor carriers (truck and bus) and hazardous materials shippers who are subject to the Federal Motor Carrier Safety Regulations (FMCSR) or Hazardous Materials Regulations (HMR).
MCMIS contains information on the safety fitness of commercial motor carriers and hazardous material (HM) shippers subject to the Federal Motor Carrier Safety Regulations and the Hazardous Materials Regulations. This information is available to the general public through the MCMIS Data Dissemination Program. MCMIS is a national data warehouse and analysis system that runs on mainframes and servers. It is developed and maintained by the FMCSA MCMIS Team in Washington, D.C. and the Volpe National Transportation Systems Center in Cambridge, Massachusetts.
Nineteen of the 51 MCMIS Crash data elements can be linked to ITS sources (Table A.7), but the detail in these crash data are not as extensive as FARS, HSIS, or GES. The P1512 Data Dictionary that collects detail on trucks involved in hazardous materials incidents supplies most of the linkages.
The MCMIS Crash File includes the National Governors' Association (NGA) recommended data elements collected on trucks and buses involved in crashes that meet the NGA-recommended crash threshold. However, these data elements were treated separately for this study. The crashes are reported by states to the FMCSA through the SAFETYNET computer reporting system. An NGA reportable crash must involve a truck (a vehicle designed, used, or maintained primarily for carrying property that has at least two axles and six tires) or bus (a passenger-carrying vehicle designed to seat at least nine people, including the driver). (The MCMIS truck definition differs from the FARS truck definition.) The crash must result in at least one fatality; one injury where the person injured is taken to a medical facility for immediate medical attention; or one vehicle having been towed from the scene as a result of disabling damage suffered in the crash.
The NGA Truck Data Elements have the most complete linkage to current ITS sources; 26 of the 37 data elements can be matched (Table A.8). The truck detail in the P1512 Data Dictionary is largely responsible for the high number of linkages.
The Hazardous Materials Incident Reporting System (HMIRS) of the Research and Special Programs Administration (RSPA) Hazardous Materials Information System was established in 1971 to fulfill the requirements of the Federal hazardous materials transportation law. It contains incident reports of carriers of hazardous materials. An unintentional release of hazardous materials meeting the criteria set forth in Section 171.16, 49 CFR, must be reported on DOT Form 5800.1.
The data from the reports received are subsequently entered in the hazmat database. Summary statistics from this data are compiled for several DOT publications, including the Secretary's Biennial Report on Hazardous Materials Transportation to Congress. Each incident report is reviewed and edited to ensure data integrity. All reports involving fatalities or injuries are analyzed and contact is made with the reporting carrier to ensure the accuracy of the information on the HMIRS.
The P1512 Data Dictionary is a rich source of data for HMIRS (Table A.9). Section 3 of P1512 covers hazardous material spills in great detail.
First established in 1973, the Grade Crossing Inventory System (GCIS) is a national database containing over 600,000 records of public and private railroad crossings in the United States along with the accident history of each crossing. Information includes the identification number, railroad, railroad division, subdivision, milepost and branch, state, county, city or nearest city, street or highway, and crossing type.
In addition, public grade-crossing information such as number of daily train movements, train speeds, type and number of tracks, details of crossing protection both active and passive, crossing angle, number of traffic lanes, daily highway traffic volume, pavement markings, advance warning signs, crossing surface, highway system, and percentage of trucks is available.
Table A.10 shows the potential of ITS sources to provide data for the GCIS. With the exception of a few geometric data items, current ITS data sources do not include data relevant for the GCIS.
