Johnson, Sara M.

Drivers often perform tasks alone or in combination that don't relate to control of their vehicle. This experiment evaluates the impact on simulated driving of performing non-driving tasks. The results showed that some of these tasks significantly degraded driving performance. The task that required drivers to use the map device caused the greatest problem. In addition, older drivers performed less well than younger drivers. The study shows objective reasons for evaluating the trade-offs between maximizing traffic safety and providing drivers with information that requires a high degree of visual attention. In the experiment, drivers performed the following secondary tasks alone, as pairs, or all three simultaneously: talking on a simulated cellular telephone, finding an object in an enclosed container, and using a special radio with head-up map and text displays. The experiment required drivers to maintain speeds of 25 to 30 miles per hour, keep the car centered in their traffic lane, and respond quickly to the appearance of simulated brake lights. Researchers divided subjects into four groups of 10 members each: young females and males with an average age of 31 and older females and males with an average age of 70.

This report presents the results of a one year comprehensive human factors analysis on the prototype Delco RDS device supplied by the Minnesota Department of Transportation. RDS devices provide a means of transmitting traffic information to motorist using the existing Traffic Management Center's resources. This study examined the devices and the means of transmitting information using ergonomic and human factors principles. This study expanded upon the functions of these devices and their ability to transmit information, as well as their integration within the automobile. The study was completed by examining the data entry tasks required to transmit messages and the TMC's operations as pertaining to messages and delivery to the end-users. Five tasks were completed with the following findings: Ergonomically, the prototype device requires further refinement to provide a user friendly interface. Linkage analysis and flow charting extracted areas where operations of the device was impeded by design. Simulation and on-road study elicited difficulty in operating the device while maintaining driving proficiency. Highly significant deviations were found between normal driving behavior and driving performance when simultaneously operating the device. This suggests an increase in attentional demand which is placed on the driver operating the device when they should be focused on the task of driving. Finally, assessment of data entry personnel and the TMC operations found several areas for improvement in the Crusader (TM) message assembly program interface and message content. Recommendations are provided following each task.

In Minnesota there is not a standard culvert design used at road crossings to improve aquatic organism or fish passage. The design process for fish passage in Minnesota is currently based on the knowledge and experience of local county, state and DNR personnel. The design methodology attempts to maintain the natural stream dimensions, pattern and profile through the culvert crossing. If designed properly aquatic organisms and fish that can make it upstream to the culvert should be able to pass through the culvert. This research was conducted to better understand the hydraulic conditions related to the practice of recessing culverts and other fish passage design elements over a range of landscapes in Minnesota. The design elements analyzed included bankfull width, slope, channel materials, side barrels and recessed culverts. Nineteen culvert sites were survey around the state. The main criterion used to evaluate performance of the culverts was the presence or absence of adequate sediment in the recessed culvert barrel. Six of the fourteen sites with recessed barrels had no sediment accumulation. A likely reason that these culverts lack sediment was increased velocities due to improper sizing relative to bankfull channel width and the accumulation of sediment in the side barrels. Wider Rosgen "C" type channels also correlated with performance issues related to culvert design.