Margaret J. Rys

Centerline Rumble Strips: Study of External Noise

Centerline rumble strips (CLRS) are patterns installed on the center of undivided, two-lane highways. Their main function is to alert drivers by producing noise and vibration. This treatment has been demonstrated to be effective in reducing crossover crashes. However, there are some disadvantages in their utilization, such as the exterior noise created by the strips. The objectives of this study were to quantify the levels of exterior noise; to verify the effects of speed, vehicle, CLRS shape, and distance on exterior noise; and to investigate the amount of noise created by CLRS that affects roadside residences and businesses. Two types of vehicles [2006 Ford Taurus (sedan) and 2008 Chevrolet Express (15 passenger van)] were driven over two different patterns of milled-in CLRS and over smooth asphalt pavement at two different speeds. Researchers collected the noise levels at three distances from the road at 10 different locations. Results indicated that vehicle type, speed, CLRS presence, and distance affect exterior noise levels. CLRS noise levels were statistically greater than smooth pavement noise levels, and the difference would be perceived by human ears at distances up to 45 meters.

The impact of training technique on the difficulty of quality improvement problem solving

A questionnaire surveying the type of training technique used (lecture, workshop, videotape, role playing, self tutorial (workbook) and self‐tutorial (computer)) for each of the seven steps in the quality improvement problem‐solving process was sent to 180 training directors in firms stating their participation in a quality improvement strategy. The training directors were then queried on the degree of difficulty experienced in executing each of the problem‐solving process steps. Evaluating the solution and final evaluation were shown to be the significantly most difficult steps to execute, and forming a team and identifying the problem were shown to be the least difficult steps; but the level of difficulty was not found to be related to the training technique used.

LOW-VOLUME ROADS AND THE GRADE CROSSING PROBLEM

Summarized are problems associated with low-volume road (LVR) passive grade crossings, low-cost innovative devices that have been developed and tested to improve safety, policies, and programs that have been developed and promoted in the United States to enhance safety at LVR grade crossings, particularly at night. On the basis of safety studies and years of experience, conclusions and recommendations are presented to reduce drivers’ risk at the typical passive, rail-highway grade crossing found on LVRs. Stressed are the two keys to reducing risk at LVR, passive grade crossings: provide adequate sight distance and make the crossing and warning devices conspicuous, particularly at night.

Safety Effectiveness of Centerline Rumble Strips in Kansas

The occurrence of roadway departure crashes is a serious problem in the United States. These types of crashes correspond to approximately 40% of all crashes in the United States, and their estimated annual cost is

Life-Cycle Economic Comparison of Common Signpost Materials and Types

100 billion. The objective of this study was to quantify the safety effectiveness of center line rumble strips (CLRS) in Kansas. CLRS are raised or grooved patterns installed on the center of two-lane, undivided, rural highways to prevent mainly cross-over crashes, more specifically head-on and sideswipe in opposite direction types of crashes. In this study, 29 sections of highways with two patterns of CLRS (rectangular and football) were analyzed, totaling more than 590 km. The naïve and the empirical Bayes before-and-after methods were applied and compared. Results showed that following the installation of CLRS, total crashes judged to be correctable by CLRS were reduced by approximately 29%. Correctable crashes involving fatalities and injuries were reduced by approximately 34%. Cross-over crashes were reduced by approximately 67%. Run-off-the-road crashes were reduced by 19%. All comparisons except for run-off-the-road crashes were statistically significant. The two methods applied presented statistically similar results. There was no statistical differences between results from sections with rectangular or football shaped CLRS.

Environmental impact of modern roundabouts

There is a wealth of information related to life-cycle costs of different sign sheeting materials and considerable information on common signposts, but there is little or no information about the life-cycle costs of different types of signposts. The primary objective of this research was to determine the best cost-effective policy, consistent with safety, for signpost materials and types used on state highways in Kansas. From the initial literature review, a matrix was constructed detailing the various materials used for signposts by each state. This was followed with a survey questionnaire to gather information on what posts other states were using for three major types of signs used in Kansas. From the data obtained from the state departments of transportation, test installations were carried out by three vendors. Life-cycle economic analysis was conducted, taking into consideration the labor, equipment, and time requirements for the initial installation and the replacement. Among the four systems compa...