1. Surface Transportation Weather: Assessment of Current Capabilities and Future Trends William Mahoney Richard Wagoner National Center For Atmospheric Research (NCAR) ITSA Annual Meeting Phoenix, AZ April 2005

2. 2 Surface transportation weather continues to gain national attention! Several road weather initiatives are in progress and new concepts are being developed. Surface Transportation Weather Trends Building a Community

3. 3 Stakeholder involvement is expanding! Surface Transportation Weather Capabilities State DOTs National Labs AMS NOAA & NASA Private Sector Auto Companies Universities AASHTO ITSA TRB Surface Transportation Weather Trends

4. 4 Where are we heading? What are the requirements? What are the opportunities? What can the science support? Surface Transportation Weather Trends

5. 5 WANTED! A seamless, high resolution, weather & road condition database of current and future conditions that can feed advanced ITS technologies such as: 511 Operations decision support Traveler information systems In-vehicle information systems Traffic management systems Control systems Surface Transportation Weather Trends Rest area kiosk Traffic Management Center

6. 6 NEEDED! Improvements in: Weather sensing (all scales) Road condition sensing Weather prediction Data fusion Information dissemination Human factors Benefits assessments Surface Transportation Weather Trends Passive surface sensor Sub pavement probe

7. 7 Weather Prediction Trends Improved horizontal resolution – 12 km heading to 5 km CONUS Need improved vertical resolution – now ~32 levels (surface to 40,000 ft) Coupled models - Land surface models - Air chemistry (pollution) - Transportation models - Fire Surface Transportation Weather Trends WRF model precipitation prediction over Colorado for MDSS Hurricane Isabel September 2003

8. 8 Data –Soil moisture –Snow cover –Albedo –Vegetation type –Greenness fraction –Soil type –Many others Feedback important for model initialization – especially for near road surface predictions. Land Surface Modeling Volumetric soil moisture at 5 cm below the ground surface simulated by HRLDAS; valid at 1200 UTC 31 May 2002. Soil Moisture Surface Transportation Weather Trends Feedback from snowfall needs to be factored into next model run!

9. 9 Surface Transportation Weather Trends Remote Sensing Acquired: October 22, 2003 VNIR – 15m IA005 IA003 IA017 IA016 Des Moines, Iowa ASTER AST07 (Surface Reflectance) AST08 (Surface Temperature) EROS Data Center NASA and NOAA satellite data: Road temperature Land surface character –Temperature –Vegetation type –Greenness fraction –Albedo –Snow cover –Land use

10. 10 Sensing Weather and Road Conditions Improvements expected in : Weather sensing (all scales) - winter precipitation gauges - video imagery Road condition sensing - optical based sensors - laser based sensors - active sensors (freeze point) Data fusion methods Information dissemination Human factors Surface Transportation Weather Trends SSI Ice Camera Vaisala Spectro Yankee Total Precipitation Sensor Lincoln Lab video Image Processing

11. 11 Surface Transportation Weather Trends Extracting & deriving weather data from vehicles: Air temperature Road friction from ABS Precip. (Y/N) from wipers Precip. intensity (wiper speed) Radar (collision avoidance) Air density Vehicle Infrastructure Integration 45 o F 44 o F 43 o F 45 o F 44 o F 38 o F

12. 12 In-Vehicle Weather Information Real time weather hazard information will be part of in- vehicle information systems Weather hazards - High winds - Tornado - Heavy snow/rain Road Hazards - Black ice - Drifting - Flooding Real-time Weather Information Here Surface Transportation Weather Trends

13. 13 Surface Transportation Weather Trends Data Fusion – Road Weather Impact Products New weather and road condition data (incl. VII and Clarus data) will be integrated into a seamless information database(s) to support: 511 In-vehicle information Traveler information Highway operations Control systems

14. 14 Surface Transportation Weather Trends Weather and Transportation Modeling Dynamic control strategies will be developed and adopted to optimize operations during poor weather conditions. Important for determining: Signal timing Ramp metering Variable speed limits Other control strategies Courtesy of the FHWA

15. 15 Surface Transportation Weather Trends Weather Challenges Need systematic approach to weather research Partnership between weather and transportation communities Targets of Opportunity  Improved road weather observing capabilities  More sophisticated forecasting systems  Applications tailored to transportation managers and users From Jeff Paniati (ITSA 2003)