Effect of a Road Safety Training Program on Drivers' Comparative Optimism

Reducing comparative optimism regarding risk perceptions in traffic accidents has been proven to be particularly difficult (Delhomme, 2000). This is unfortunate because comparative optimism is assumed to impede preventive action. The present study tested whether a road safety training course could reduce drivers' comparative optimism in high control situations. Results show that the training course efficiently reduced comparative optimism in high control, but not in low control situations. Mechanisms underlying this finding and implications for the design of road safety training courses are discussed.

Road Equipment Procurement and Utilization Study, October 2002

Final report of road equipment procurement and utilization study.

An Investigation of User Costs and Benefits of Winter Road Closures, June 2005

This project explores the user costs and benefits of winter road closures. Severe winter weather makes travel unsafe and dramatically increases crash rates. When conditions become unsafe due to winter weather, road closures should allow users to avoid crash costs and eliminate costs associated with rescuing stranded motorists. Therefore, the benefits of road closures are the avoided safety costs. The costs of road closures are the delays that are imposed on motorists and motor carriers who would have made the trip had the road not been closed. This project investigated the costs and benefits of road closures and found that evaluating the benefits and costs is not as simple as it appears. To better understand the costs and benefits of road closures, the project investigates the literature, conducts interviews with shippers and motor carriers, and conducts case studies of road closures to determine what actually occurred on roadways during closures. The project also estimates a statistical model that relates weather severity to crash rates. Although, the statistical model is intended to illustrate the possibility to quantitatively relate measurable and predictable weather conditions to the safety performance of a roadway. In the future, weather conditions such as snow fall intensity, visibility, etc., can be used to make objective measures of the safety performance of a roadway rather than relying on subjective evaluations of field staff. The review of the literature and the interviews clearly illustrate that not all delays (increased travel time) are valued the same. Expected delays (routine delays) are valued at the generalized costs (value of the driver’s time, fuel, insurance, wear and tear on the vehicle, etc.), but unexpected delays are valued much higher because they result in interruption of synchronous activities at the trip’s destination. To reduce the costs of delays resulting from road closures, public agencies should communicate as early as possible the likelihood of a road closure.

The policy relevance of wear emissions from road transport, now and in the future : an international workshop report and consensus statement

Road transport emissions are a major contributor to ambient particulate matter concentrations and have been associated with adverse health effects. Therefore, these emissions are targeted through increasingly stringent European emission standards. These policies succeed in reducing exhaust emissions, but do not address "nonexhaust" emissions from brake wear, tire wear, road wear, and suspension in air of road dust. Is this a problem? To what extent do nonexhaust emissions contribute to ambient concentrations of PM10 or PM2.5? In the near future, wear emissions may dominate the remaining traffic-related PM10 emissions in Europe, mostly due to the steep decrease in PM exhaust emissions. This underlines the need to determine the relevance of the wear emissions as a contribution to the existing ambient PM concentrations, and the need to assess the health risks related to wear particles, which has not yet received much attention. During a workshop in 2011, available knowledge was reported and evaluated so as to draw conclusions on the relevance of traffic-related wear emissions for air quality policy development. On the basis of available evidence, which is briefly presented in this paper, it was concluded that nonexhaust emissions and in particular suspension in air of road dust are major contributors to exceedances at street locations of the PM10 air quality standards in various European cities. Furthermore, wear-related PM emissions that contain high concentrations of metals may (despite their limited contribution to the mass of nonexhaust emissions) cause significant health risks for the population, especially those living near intensely trafficked locations. To quantify the existing health risks, targeted research is required on wear emissions, their dispersion in urban areas, population exposure, and its effects on health. Such information will be crucial for environmental policymakers as an input for discussions on the need to develop control strategies.

Tree and Brush Control For County Road Right-of-Way, Ocotober 2002

This manual summarizes the roadside tree and brush control methods used by all of Iowa's 99 counties. It is based on interviews conducted in Spring 2002 with county engineers, roadside managers and others. The target audience of this manual is the novice county engineer or roadside manager. Iowa law is nearly silent on roadside tree and brush control, so individual counties have been left to decide on the level of control they want to achieve and maintain. Different solutions have been developed but the goal of every county remains the same: to provide safe roads for the traveling public. Counties in eastern and southern Iowa appear to face the greatest brush control challenge. Most control efforts can be divided into two categories: mechanical and chemical. Mechanical control includes cutting tools and supporting equipment. A chain saw is the most widely used cutting tool. Tractor mounted boom mowers and brush cutters are used to prune miles of brush but have significant safety and aesthetic limitations and boom mowers are easily broken by inexperienced operators. The advent of tree shears and hydraulic thumbs offer unprecedented versatility. Bulldozers are often considered a method of last resort since they reduce large areas to bare ground. Any chipper that violently grabs brush should not be used. Chemical control is the application of herbicide to different parts of a plant: foliar spray is applied to leaves; basal bark spray is applied to the tree trunk; a cut stump treatment is applied to the cambium ring of a cut surface. There is reluctance by many to apply herbicide into the air due to drift concerns. One-third of Iowa counties do not use foliar spray. By contrast, several accepted control methods are directed toward the ground. Freshly cut stumps should be treated to prevent resprouting. Basal bark spray is highly effective in sensitive areas such as near houses. Interest in chemical control is slowly increasing as herbicides and application methods are refined. Fall burning, a third, distinctly separate technique is underused as a brush control method and can be effective if timed correctly. In all, control methods tend to reflect agricultural patterns in a county. The use of chain saws and foliar sprays tends to increase in counties where row crops predominate, and boom mowing tends to increase in counties where grassland predominates. For counties with light to moderate roadside brush, rotational maintenance is the key to effective control. The most comprehensive approach to control is to implement an integrated roadside vegetation management (IRVM) program. An IRVM program is usually directed by a Roadside Manager whose duties may be shared with another position. Funding for control programs comes from the Rural Services Basic portion of a county's budget. The average annual county brush control budget is about $76,000. That figure is thought not to include shared expenses such as fuel and buildings. Start up costs for an IRVM program are less if an existing control program is converted. In addition, IRVM budgets from three different northeastern Iowa counties are offered for comparison in this manual. The manual also includes a chapter on temporary traffic control in rural work zones, a summary of the Iowa Code as it relates to brush control, and rules on avoiding seasonal disturbance of the endangered Indiana bat. Appendices summarize survey and forest cover data, an equipment inventory, sample forms for record keeping, a sample brush control policy, a few legal opinions, a literature search, and a glossary.

Impacts of Rural Development on Iowa’s Secondary Road Systems, TR-548, September 2010

Today, many of Iowa’s counties are experiencing an increase in rural development. Two specific types of development were focused on for this research: rural residential subdivisions and livestock production operations. Rural residential developments are primarily year round single-family homes, though some are vacation homes. Livestock production in Iowa includes hog, beef, and poultry facilities. These two types of rural development, while obviously very different in nature and incompatible with each other, share one important characteristic: They each generate substantial amounts of new traffic for Iowa’s extensive secondary road system. This research brings together economic, spatial, and legal analysis methods to address the impacts of rural development on the secondary road system and provide county engineers, county supervisors, and state legislators with guidance in addressing the challenges associated with this development.

Effect of Wildlife Highway Warning Reflectors on Deer-Vehicle Accident, December 1984

he number of deer-vehicle accidents in Iowa and around the country has steadily increased during the past 30 years. This i s basically due to: ( 1 ) increased volume of traffic; 12) an expanding network of hard surface roads, especially 4 lane interstates; and (3) a general increase in deer populations. Initidtion of a 55 MPH speed limit in 1974 and gasoline shortages in 1975 reduced deer-vehicle accident rates briefly, but since 1975, rates have continued to climb. Various methods of reducinq these accidents have been attempted in other states. These include: instal lation of rc?flective devlres, deer crossing signs, fencing, underpasses, clearing right--of--waysa,n d controlled hunting to reduce deer population s i z e . These methods have met with varying degrees of success, depending on animal behavior, deet- population fluctuations, method used, topoyr-aphy, road-side vegetation, traffic patterns, and highway configuration. This project was designed to evaluate a new ntethod of reducing deer-vehicle accidents. There are qenerally 4 important aspects of deer-vehicle accidents: danger to human l i f e , vehicle damage, loss of a valuable wildlife resource, and cost of processing accident reports. In !owe, during 1983, there were over 15,OOC) reported deer--vehicle accidents and probably many more that were not reported (Gladfelter 1984). The extent of human injury or death in Iowa i s not known, but studies in southern Michigan show that human injur ies occurred in about 4% of the deer-vehicle accidents (A1 lcn and MrCullough 1976). T h i s would indicate that in Iowa there could have been 200 human injury cases from deer-vehicle accidents i n 1983. These injuries usual 1 occur from secondary collisions when motorists try to avoid a deer on the highway, and hit some other object Vehicle darnaye from these accidents can into thousands of dollars because of the high speed involved and the size of the animal. The total amount of vehicle damage occurring in Iowa is unknown, but if the average vehicle damage was between $500-$800 per accident, estimated property damage would be between $2 1/2--$4 million annually. The value of deer lost in these accidents cannot be estimated, but recreational potential of this natural resource is surely diminished for hunters and wildlife enthusiasts. Also, there ir a great deal of money spent by governmental agencies for manpower to process accident reports and remove dead animals from highways.

Utilization of Remote Traffic Monitoring Devices for Urban Freeway Work Zone Assessment Final Report, January 2012

The objective of this project was to promote and facilitate analysis and evaluation of the impacts of road construction activities in Smart Work Zone Deployment Initiative (SWZDI) states. The two primary objectives of this project were to assess urban freeway work-zone impacts through use of remote monitoring devices, such as radar-based traffic sensors, traffic cameras, and traffic signal loop detectors, and evaluate the effectiveness of using these devices for such a purpose. Two high-volume suburban freeway work zones, located on Interstate 35/80 (I-35/I-80) through the Des Moines, Iowa metropolitan area, were evaluated at the request of the Iowa Department of Transportation (DOT).

Road Safety Audit for the Intersection of US 59 and IA 9 in Osceola County, Iowa Final Report, March 2012

The Iowa Department of Transportation (DOT) requested a road safety audit (RSA) of the US 59/IA 9 intersection in northwestern Iowa, just south of the Minnesota border, to assess intersection environmental issues and crash history and recommend appropriate mitigation to address the identified safety issues at the intersection. Although the number of crashes at the location has not been significantly higher than the statewide average for similar intersections, the severity of these crashes has been of concern. This RSA was unique in that it included intersection video observation and recorded traffic conflict data analysis, along with the daylight and nighttime field reviews. This report outlines the findings and recommendations of the RSA team for addressing the safety concerns at this intersection.

Use of Incentive/Disincentive Contracting to Mitigate Work Zone Traffic Impacts, 2012

Incentive/disincentive clauses (I/D) are designed to award payments to contractors if they complete work ahead of schedule and to deduct payments if they exceed the completion time. A previously unanswered question is, “Did the costs of the actual work zone impacts that were avoided justify the incentives paid?” This report answers that question affirmatively based on an evaluation of 20 I/D projects in Missouri from 2008 to 2011. Road user costs (RUC) were used to quantify work zone impacts and included travel delays, vehicle operating costs, and crash costs. These were computed using work zone traffic conditions for partial-closure projects and detour volumes and routes for full-closure projects. Conditions during construction were compared to after construction. Crash costs were computed using Highway Safety Manual methodology. Safety Performance Functions produced annual crash frequencies that were translated into crash cost savings. In considering an average project, the percentage of RUC savings was around 13% of the total contract amount, or $444,389 of $3,464,620. The net RUC savings produced was around $7.2 million after subtracting the approximately $1.7 million paid in incentives. In other words, for every dollar paid in incentives, approximately 5.3 dollars of RUC savings resulted. I/D provisions were very successful in saving RUC for projects with full-closure, projects in urban areas, and emergency projects. Rural, non-emergency projects successfully saved RUC but not at the same level as other projects. The I/D contracts were also compared to all Missouri Department of Transportation contracts for the same time period. The results show that I/D projects had a higher on-time completion percentage and a higher number of bids per call than average projects. But I/D projects resulted in 4.52% higher deviation from programmed costs and possibly more changes made after the award. A survey of state transportation departments and contractors showed that both agreed to the same issues that affect the success of I/D contracts. Legal analysis suggests that liquidated damages is preferred to disincentives, since enforceability of disincentives may be an issue. Overall, in terms of work zone impact mitigation, I/D contracts are very effective at a relatively low cost.

An Investigation of Signing Needs at Uncontrolled Local Road Intersections, HR-230, 1982

Iowa Counties have been experiencing significant tort claim liability due to the signing of local roads. One such problem is relative to the real or alleged need for signing at uncontrolled intersections of local roads. It has been assumed that the standard CROSS ROAD sign, which calls for a yellow diamond with a black cross, was sufficient to provide the necessary warning that a driver may be approaching an intersection which requires special precautionary driving attention. However, it is possible that this sign on a through highway might conflict with the legal status of the local county road. In light of this situation, it seemed worthwhile to know the extent to which uncontrolled local road intersections were perceived as a potential liability problem; the degree to which the standard CROSS ROAD sign communicated to the driver the message a county engineer wanted at these local road intersections; and whether there were any better signing alternatives available to communicate this hazard to the driver in this situation.

Liability and Traffic Control Considerations for Low Water Stream Crossings, HR-218, 1981

The current shortage of highway funds precludes the immediate replacement of most of the bridges that have been evaluated as structurally deficient or functionally obsolete or both. A low water stream crossing (LWSC) affords an economical alternative to the replacement of a bridge with another bridge in many instances. However, the potential liability that might be incurred from the use of LWSCs has served as a deterrent to their use. Nor have guidelines for traffic control devices been developed for specific application to LWSCs. This research addressed the problems of liability and traffic control associated with the use of LWSCs. Input to the findings from this research was provided by several persons contacted by telephone plus 189 persons who responded to a questionnaire concerning their experience with LWSCs. It was concluded from this research that a significant potential for accidents and liability claims could result from the use of LWSCs. However, it was also concluded that this liability could be reduced to within acceptable limits if adequate warning of the presence of an LWSC were afforded to road users. The potential for accidents and liability could further be reduced if vehicular passage over an LWSC were precluded during periods when the road was flooded. Under these conditions, it is believed, the potential for liability from the use of an LWSC on an unpaved, rural road would be even less than that resulting from the continuing use of an inadequate bridge. The signs recommended for use in advance of an LWSC include two warning signs and one regulatory sign with legends as follows: FLOOD AREA AHEAD, IMPASSABLE DURING HIGH WATER, DO NOT ENTER WHEN FLOODED. Use of the regulatory sign would require an appropriate resolution by the Board of Supervisors having responsibility for a county road. Other recommendations include the optional use of either a supple mental distance advisory plate or an advisory speed plate, or both, under circumstances where these may be needed. It was also recommended HR-218 Liability & Traffic Control Considerations for Low Water Stream Crossings that LWSCs be used only on unpaved roads and that they not be used in locations where flooding of an LWSC would deprive dwelling places of emergency ground access.

Maintaining Iowa's Secondary Road Environment, HR-289, 1989

The Iowa counties have been successful in maintaining a good roadway environment on our 90,000 mile secondary road system. However, county highway personnel must remain vigilant in detecting, discovering and correcting potential problems if our roads are to remain so. This presentation was developed for those county personnel who work and travel on secondary roads. The presentation discusses things county personnel can look for during their daily operations which could possibly create a potential problem. If these situations are uncovered and corrected in a timely manner, our secondary road system will be maintained in an appropriate manner.

Correlation Studies BPR Type Roughometer vs. PCE Type Road Meter, MLR-68-2, 1968

The BPR type Roughometer has been used by the Iowa State Highway Commission since 1955 for the evaluation of the relative roughness of the various Iowa road surfaces. Since the commencement of this program, standardized information about the roughness of the various Iowa roads with respect to their type, construction, location and usage has been obtained. The Roughometer has also served to improve the economics and quality of road construction by making the roughness results of various practices available to all who are interested. In 1965, the Portland Cement Association developed a device known as the PCA Road Meter for measuring road roughness. Mounted in a regular passenger car, the Road Meter is a simple electromechanical device of durable construction which can perform consistently with extremely low maintenance. In 1967, the Iowa State Highway Commission's Laboratory constructed a P.C.A. type Road Meter in order to provide an efficient and reliable method for measuring the Present Serviceability Index for the state's highways. Another possibility was that after considerable testing the Road Meter might eventually replace the Roughometer. Some advantages of the Road Meter over the Roughometer are: (1) Road Meter tests are made by the automobile driver and one assistant without the need of traffic protection. The Roughometer has a crew of four men; two operating the roughometer and two driving safety vehicles. (2) The Road Meter is able to do more miles of testing because of its faster testing speed and the fa.ct that it is the only vehicle involved in the testing. (3) Because of the faster testing speed, the Road Meter gives a better indication of how the road actually rides to the average highway traveler. (4) The cost of operating a Road Meter is less than that of a Roughometer because of the fewer number of vehicles and men needed in testing.

Evaluation of Gateway and Low-Cost Traffic-Calming Treatments for Major Routes in Small, Rural Communities, TR-523, 2007

Many rural communities have developed around highways or major county roads; as a result, the main street through small rural communities is often part of a high-speed rural highway. Highways and county roads are characterized by high speeds outside the city limits; they then transition into a reduced speed section through the rural community. Consequently, drivers passing through the community often enter at high speeds and maintain those speeds as they travel through the community. Traffic calming in small rural communities along major roadways is common in Europe, but the U.S. does not have experience with applying traffic-calming measures outside of major urban areas. The purpose of the project was to evaluate traffic-calming treatments on the major road through small Iowa communities using either single-measure low-cost or gateway treatments. The project was partially funded by the Iowa Highway Research Board (IHRB). The focus of the IHRB portion was to evaluate single-measure, low-cost, traffic-calming measures that are appropriate to major roads through small rural communities. Seven different low-cost traffic treatments were implemented and evaluated in five rural Iowa communities. The research evaluated the use of two gateway treatments in Union and Roland; five single-measure treatments (speed table, on-pavement “SLOW” markings, a driver speed feedback sign, tubular markers, and on-pavement entrance treatments) were evaluated in Gilbert, Slater, and Dexter.