Roadside Design Guide


Book Description

This document presents a synthesis of current information and operating practices related to roadside safety and is developed in metric units. The roadside is defined as that area beyond the traveled way (driving lanes) and the shoulder (if any) of the roadway itself. The focus of this guide is on safety treatments that minimize the likelihood of serious injuries when a driver runs off the road. This guide replaces the 1989 AASHTO "Roadside Design Guide."







Identification of Vehicular Impact Conditions Associated with Serious Ran-off-road Crashes


Book Description

TRB's National Cooperative Highway Research Program (NCHRP) Report 665: Identification of Vehicular Impact Conditions Associated with Serious Ran-off-Road Crashes quantifies the characteristics of ran-off-road crashes and identifies appropriate impact conditions for use in full-scale crash testing.







Evaluation of Safety Treatments for Roadside Culverts


Book Description

Roadside cross-drainage culverts have been found to impact vehicle accident injury levels. Designers have commonly used three safety treatments to protect errant drivers from culvert accidents. These treatments have included: culvert extension, guardrail installation and grating. In order to define which safety treatment is the most appropriate, benefit-cost analysis has used accident cost reduction to estimate societal gains earned by using any safety treatment. The purpose of this study was to estimate accident costs for a wide range of roadway and roadside characteristics so that designers can calculate benefit/cost ratios for culvert safety treatment options under any particular scenario. This study began with conducting a parametric study in order to find variables which have significant impact on accident cost changes. The study proceeded with highway scenario modeling which included scenarios with different values for combinations of roadway and roadside variables. These variables were chosen based upon findings from the parametric study and their values were assigned based upon highway classification. This study shows that the use of different culvert safety treatments should be flexible to roadway and roadside characteristics. It also shows that culvert extension and grating were the safety treatments found to produce the lowest accident costs for all highway scenarios modeled. Therefore, it is believed that the expanded adoption of culvert extension and culvert grates can improve overall highway safety.




An Asset Management Approach for Drainage Infrastructure and Culverts


Book Description

Drainage infrastructure systems (culvert, storm sewer, outfall and related drainage elements) are mostly buried underground and are in need of special attention in terms of proactive/preventive asset management strategy. Drainage infrastructure systems represent an integral portion of roadway assets that routinely require inspection, maintenance, repair and renewal. Further challenges are the wide geospatial distribution of these infrastructure assets and environmental exposure. There has been considerable research conducted on culverts, but mostly looked at the problem from a traditional structural/geotechnical perspective. Asset management procedures for culverts and drainage infrastructure systems are complex issues, and can benefit a great deal from an optimal asset management program that draws from programs pertaining to buried pipes. The first and most important step in an asset management initiative is the establishment of mechanism for asset inventory and asset conditions in a format compatible with the routine procedures of field operators and inspectors. The first objective of this research project was to develop field protocols and operational business rules for inventory data collection and management and inspection of drainage infrastructures in terms of types of data to be collected, frequency of inspection, and analysis and reporting mechanisms. After review of these protocols by the project oversight committee, a pilot study was conducted to verify efficiency of their implementation. The condition assessment protocol introduced is useful in evaluating the overall condition of culverts and can be used for decision making regarding the repair, renewal or replacement of culverts. For the second objective of this project, investigators examined the inventory and inspection protocols employed by Ohio Department of Transportation (ODOT) and developed a decision support platform, which establishes a link between the inspection results and appropriate repair, renewal and replacement procedures. After applying the recommended procedures, the transportation agencies can better track the conditions of culverts thereby reducing the risks of culvert failures.







Facilities Development Manual


Book Description