Cover Image

Not for Sale



View/Hide Left Panel
Click for next page ( 63


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 62
62 HAM-IR-75 Work Zone Crash Location-Frequency Chart Exception Location: Review Crash Reports and Field Review 70 Boxes Contain Pre Work Zone 3-Year Averages by Section (April 1 - November 64 30) 60 39 Exception Location: 38 Number of Crashes 50 Review Crash Reports and Field Review 31 40 34 30 30 19 19 20 10 8 3 10 7 3 0 0 14.27 - 14.76 14.77 - 15.26 15.27 - 15.76 15.77 - 16.26 16.27 - 16.76 16.77 - 17.26 17.27 - 17.76 Crash Logpoint (MP 14.2 - 17.4) HAM-IR-75 Count of Crashes in Work Zone by Month 30 Pre Work Zone 3-Year Monthly Average: 18 Crashes HAM-IR-75 Work Zone vs. Non Work Zone Crash Comparison 25 148 137 160 Number of Crashes 20 140 Number of Crashes 120 15 100 80 60 10 40 20 5 0 2004 Work Zone Crashes Pre Work Zone 3-Yr Average 0 1 2 3 4 5 6 7 8 9 Month (Numerical Value) Figure 29. Example of work zone crash analysis performed by Ohio DOT (76). points presented in the table illustrates that both approaches that any modifications made to them are actually reducing have a significant role within highway agencies as they strive to crash risk. improve safety within the work zones under their jurisdiction. Perhaps more importantly, there is a degree of synergy between Summary the two main analysis approaches. Monitoring efforts are best suited to identify possible safety issues at the project Although no work zone crash data system currently in use level that may be quickly mitigated by the agency or the con- fully addresses the needs of effective work zone safety manage- tractor. Monitoring efforts can be an effective method of ment, it appears that such a system can be developed by com- identifying possible work zone design features, operating bining the desirable features of the MMUCC with an agency strategies, etc. that may be unduly contributing to crashes construction accident reporting program similar in concept occurring in work zones and so need to be modified. Post- to the one now in use at NYSDOT. However, revisions and hoc investigations are more suited to actually quantifying the improvements to both of these are considered essential to extent to which those features and operating strategies are con- achieve the goal of providing comprehensive, timely, and tributing to work zone crashes and to quantifying the extent consistent data for crashes, construction accidents, and other

OCR for page 62
63 Table 25. Comparison of monitoring and post-hoc crash analysis approaches. Crash Monitoring Post-Hoc Investigations Opportunities Allows for near real-time identification of Allows for quantification of influence of work possible safety problems (features, strategies, zone feature(s), operating strategies, and safety etc.) countermeasures implemented Demonstrates a culture of diligence about work Allows experiences from multiple work zones zone safety by the agency (potentially useful to be properly consolidated and interpreted for litigation purposes) (useful for periodic assessment of agency policies and processes) Challenges Requires commitment by the agency to collect Difficult to know what feature(s) or operating and process data in a timely manner strategies are the highest priority to investigate Difficult to determine relative contributions of Typically requires more data to perform multiple features or strategies to a possible correctly safety problem Often a significant time lag exists between when a crash occurs and the time it is available for analysis harmful events in and related to highway work zones. Specif- accepted terminology. The MMUCC data elements are clas- ically, the following actions would be needed: sified into four major groups crash, motor vehicle, person, and roadway data. With the corrections and revisions dis- The MMUCC guideline needs to be implemented by more cussed in the previous sections, the MMUCC data elements states to permit sharing of data between states. would be sufficient to provide much of the information Minor modifications to the MMUCC guideline should be needed for vehicle-involved crashes. However, it includes no made to address the weaknesses and inconsistencies dis- data elements to address work zone accidents by pedestrians cussed in the preceding sections. and bicycles but not involving a vehicle, and no elements for Some roadway data elements in the MMUCC guideline are construction accidents. In addition, there are insufficient recorded in the field, while others are obtained through elements to identify all of the specific types of work zone traf- linkage to other roadway databases. Because roadway char- fic control devices and safety features present or involved in acteristics are frequently temporarily changed in work the crash, other than a few included in other data elements zones, the linked roadway data included in the MMUCC such as "Traffic Control Device Type." In addition, there are may be invalid for work zone crashes. Therefore, it appears no elements to describe work vehicles, equipment, and work necessary to verify these linked roadway elements in the operations. field at the time of a work zone crash, or to establish pro- These lacking data elements can best be addressed by de- cedures that would allow work zone roadway element fea- veloping a comprehensive list of data elements and attributes tures present at the time of the crash to be determined via to be incorporated into a work zone crash/accident reporting construction plans, project diary documentation, or other program to be implemented by highway agencies as a supple- mechanisms. ment to MMUCC or similar crash reports. Such a compre- While the NYSDOT system is conceptually sound, there hensive list should have a strong consensus of support from are inherent weaknesses in it that need to be corrected. highway agencies in this country. These data elements would These involve revising some data elements and attributes include the following four groups: and adding others. The reliance on true/false attributes should be replaced by standard attributes associated with Project and crash identification elements--A series of ele- specific data elements to facilitate use of the database. ments would identify the date, time, and location of the A nationally supported research effort either by FHWA or event and the contract or permit where the event occurs. through the NCHRP program appears to be the most prac- An element could be included to identify agency region or tical means to develop a model state system, using the district as well as project type (reconstruction, bridge re- NYSDOT program as a starting point, and revising and habilitation, safety improvement project, etc.). Involved expanding it to address its weaknesses. contractors, subcontractors, and consultants would also be identified. A tracking number would be included for each The proposed list of data elements and attributes for work event. zone crashes addresses specific characteristics of work zone Work zone elements--These elements would identify com- crashes and accidents using attributes based on generally monly used work zone traffic control devices, traffic safety

OCR for page 62
64 features, and construction safety features and devices. Also equivalent accident reports are available in a timely manner included would be elements to describe work vehicles and to supplement the agency internal report, this information equipment involved and the related work operations. could be available as needed. In reality, however, some delay Supplemental person elements--These elements would pro- will be encountered in obtaining MMUCC or other similar vide information about workers involved, including job reports prepared by police agencies, and more critically not title, employer, etc. all crashes and events will generate a police report. Therefore, Report tracking elements--These elements would identify it is important to duplicate certain data elements from the persons involved in preparing and reviewing the report, MMUCC into the work zone crash/accident reporting pro- report dates, etc. They would be used for internal agency gram to ensure that the necessary information is available in management purposes and are not directly associated with a timely manner for all events. These elements are identified crash or accident safety management. in the column "Work Zone Related" in Appendix C. While the above categories of elements are thought to in- In addition to these data elements to be addressed solely in clude those most relevant to work zone safety management, the work zone crash/accident reporting program, the pro- individual highway agencies could have the option to add posed system will also rely on numerous data elements in- any additional elements considered important for internal cluded in the MMUCC. To the extent that the MMUCC or purposes.