Minnesota Department of Transportation (Mn/DOT) needs improved traffic monitoring tools to optimally allocate road maintenance and improvement resources. In particular, the department needs a method of including vehicle and axle weights with portable traffic logging equipment. The cost of existing Weigh-in-Motion (WIM) equipment prevents widespread use in locations where only temporary monitoring is needed. This project was a survey of the suppliers of portable WIM systems, allowing a few systems to be moved between locations of interest. There were four candidate systems found and studied, of which two are recommended for further evaluation. Both systems appear to meet the needs Mn/DOT established and local testing will allow a final decision on their suitability.
The goal of this project was to understand the effectiveness of light emitting diode (LED) based lights for replacement of the standard strobes on Mn/DOT snow plows and to develop a set of specifications for LED based snow plow strobe lights. Intensity measurements were performed along with field testing in order to understand the correlation between optical power output of the lights and the conspicuity of the lights under typical viewing conditions. A robust correlation between intensity and conspicuity was not established, but we were able to make a qualitative connection between intensity and conspicuity for the LED based lights under the conditions tested. The results suggest that LED based lights are comparable in conspicuity to the standard strobe lights currently used on Mn/DOT plows, under specific conditions. We found that when viewed from a direction corresponding to that typical of a vehicle approaching from the rear; the LED based lights were equally conspicuous as the standard strobe. However, when viewed from other angles the standard strobe outperforms the LED lights in field tests. A specification was not completed, but recommendations were made for possible improvements to LED based lights to improve field test results.
Centerline rumble strips are being installed on rural Minnesota Highways in an effort to reduce crossover accidents. This study looks for possible detrimental effects on 2 and 3 wheeled cycles. Motorcycle accidents reports since centerline rumble strips first appeared on rural highways in 1999 revealed only 29 accidents on roads with the rumble strips. None of these reports implicated the rumble strips as a factor in the accident. There were also no visible indications of rider correction or overcorrection in 40 hours of roadside observations. Controlled conditions on a closed circuit supported this observation through 32 riders in all types of cycles and experience levels from 0 to 41 years of street riding. Interviews confirmed that the riders had no difficulty or concern with the rumble strips. The recommendation from this study is that cyclist should become familiar with the rumble strips in rider safety courses and driving examinations. There were no indications to impede the installation of rumble strips and no indication that signage is justified.
