Maintenance services and surface weather TRB Transportation Research Record: Journal of the Transportation Research Board No. 2169 contains 19 papers that explore variable speed limit systems in work zones the safety of mobile lane closures temporary rumble strips for short term work zones the joint merge in construction zones real time measurement of travel time delay in work zones short term speed limit devices in work zones simulation models for assessing the impacts of highway work zone strategies and estimating operational impacts of freeway work zones on extended facilities. This issue of the TRR also examines alternative displays for speed limits in work zones assessment of pavement marking visibility repeatability of retroreflectometer measurements of pavement markings impact of cold temperature and snowfall on traffic volume diagnosing road weather conditions with vehicle probe data improving road weather hazard products with vehicle probe data integrating the impact of rain into traffic management the impact of adverse weather on freeway free flow speed structural control measures to mitigate avalanche hazards a small unmanned aircraft for avalanche control and costs and benefits of tools to maintain winter roads