Summary• The influence of vesicular-arbuscular mycorrhizal ( VAM) host plants is reported on VAM infection of Quercus rubra seedlings, a predominately ectomycorrhizal species.• In a field experiment, Q. rubra seedlings were planted near Quercus montana and Acer rubrum (a VAM host) stump sprouts and near dead Quercus spp. stumps. In a subsequent glasshouse study, seedlings of Q. rubra were grown with or without VAM inoculum ( ± V) and with or without Sorghum bicolor ( ± S), a VAM host.• In the field experiment, seedlings planted near A. rubrum had greater VAM infection than other seedlings; ectomycorrhizal infection was greatest on seedlings near Q. montana . In the glasshouse experiment, VAM infection was increased in both extent (proportion of root length infected in roots of infected seedlings) and frequency (number of seedlings with infection) in the presence of S. bicolor . Seedling mass and N concentration were reduced in the + V treatment; however, these variables were not correlated with extent of VAM infection.• VAM infection of Q. rubra is greatly enhanced in the presence of VAM hosts in both field and glasshouse conditions. No evidence for positive effects of VAM infection on Q. rubra seedlings was found.

Strategies to reduce pedestrian-vehicle crashes at intersections should be investigated. Implementation of the leading pedestrian interval (LPI) has been recommended as a strategy for reducing pedestrian-vehicle crashes at signalized intersections; however, research on quantification of the safety effects of the LPI has been limited. Site characteristics, traffic volumes, pedestrian volumes, and crash data were obtained for 10 signalized intersections where the LPI was implemented in State College, Pennsylvania. Similar data were obtained for 14 stop-controlled intersections within the State College area. A before-after with comparison group study design was used to evaluate the safety effectiveness of the LPI implementations. The results suggest a 58.7% reduction in pedestrian-vehicle crashes at treated intersections, which is statistically significant at the 95% confidence level. An economic analysis was also conducted to determine the cost-effectiveness of the strategy. Given the low cost of this strategy, only a modest reduction in crashes is needed to justify its use economically. On the basis of the estimated safety effectiveness, the necessary crash reduction is easily achievable.

A study of the usability of statewide web-based traveler information systems was conducted to assess their effectiveness in conveying road and weather information to travelers. Guidelines from traveler information systems and the website design literature were coalesced to create an assessment framework to include important elements from a user’s perspective. Ninety-eight travelers from the State College, Pennsylvania, area visited web-based roadway weather information systems for Pennsylvania, Maryland, and Ohio as part of a laboratory-based trip-planning experiment and provided ratings of site attributes. Site ratings revealed that it was important that travelers accessed information about conditions along their intended route with minimal searching. Map scale and resolution were important graphical elements. The most relevant weather information elements identified by users were precipitation type, road surface condition, visibility, and air temperature.

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