Excessive speed is one of the most significant factors contributing to work zone crashes, which, along with work zone fatalities, have increased substantially in the past decade. From the beginning of 2000 to the end of 2003, the number of work zone crashes in South Carolina nearly tripled. In 2005, the South Carolina Department of Transportation initiated a research project to evaluate speed reduction measures in work zones. Through an in-depth literature review of speed control techniques for work zones, it was found that innovative technologies are often too expensive and thus impractical for large-scale implementation. There is a need for less-expensive technologies that are effective in reducing speeds in work zones. Development and evaluation of a speed-activated sign are discussed. Data were collected in work zones on two-lane primary and secondary highways in South Carolina, and the effectiveness of the speed-activated sign was evaluated on the basis of changes in mean speeds, 85th-percentile speeds, and percentages of vehicles exceeding the speed limit. Mean speed reductions ranged from 2 to 6 mph (3.2 to 9.7 km/h) with an average reduction of 3.3 mph (5.3 km/h). This average reduction improved to 4.1 mph (6.6 km/h) at sites where more than 50% of the vehicles were speeding before a sign was introduced. Further research was conducted with two speed-activated signs on a multilane divided highway and an Interstate freeway where similar speed reductions were experienced. From this study, researchers recommend that the speed-activated sign be used in short-term work zones.

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The U.S. National Park Service has worked to reduce traffic congestion in parks through a transit service. Consistently, communities around parks that are planning for transit want to know what effects they will experience from introductions or changes in service. This research developed a comprehensive understanding of the encountered effects. Seven case study investigations revealed no clear patterns in visitation changes at parks with recent transit initiatives. Circulation and economic impacts depended on local situations and followed from transit planning decisions. The case study findings provide models that can inform planning for continued expansion of transit on public lands.

Although parking is an important issue in transportation engineering and planning, little research has examined the use of new parking information technologies in rural communities. The Clemson University campus, in South Carolina, was used as a case study to determine the ability of roadside parking information systems to reduce delay, cut travel time, and manage changing volumes of cars. To examine these effects, a traffic simulation model of the campus was built, calibrated, and validated. The model used a dynamic assignment approach to capture the rerouting of vehicles in response to parking availability information for several key parking lots. It was found that use of roadside parking information systems, such as dynamic message signs, can reduce delay while not significantly affecting volumes, travel times, or speeds. The findings suggested that delay reduction was caused by a decrease in vehicle circulation time.

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