Economic Impact of Closing Low-Volume Rural Bridges in Kansas Eric J. Fitzsimmons, Ph.D.

1. Economic Impact of Closing Low-Volume Rural Bridges in Kansas Eric J. Fitzsimmons, Ph.D. Tom Mulinazzi, Ph.D., P.E., L.S. Steven D. Schrock, Ph.D., P.E. Mid-Continent Transportation Research Symposium Ames, Iowa August 15-16, 2013 Session 3F: Local Roads Considerations

2. Background and Objectives • The state of Kansas has approximately 25,500 bridges • Limited county resources restrict rebuilding or repairing bridges • Structurally deficient bridges • Functionally obsolete bridges • Bridge inspection and engineering studies have shown the need to close or repair/replace a low-volume bridge • The decision to act on this lies with the county commissioners

3. Study Objective and Research Gap • To determine a cost comparison of replacing and/or repairing a rural low volume structurally deficient bridge versus closing the bridge and finding the change in vehicle operating cost based on the proposed driver detour • Very limited research in this area, however studies have investigated closing segments of rural roadway – particularly in Kansas (Babcock and Alakshendra, 2012)

4. KDOT Data • National Bridge Inventory Database • Two-wheel path unpaved roads (very low volume) • Average Daily Traffic (ADT) = 25 vehicles per day or less • 1,321 bridges met this criteria

5. Data Reduction and Detour Length Determination • Each bridge was verified that it existedthrough Google maps • Inspection dates were as far back as 1994 • Variables included • Latitude/Longitude, structure type, inspection date, deck area • In many cases bridges were removed or culvert installed • 992 total bridges were found to exist in the data set

6. Data Reduction and Detour Length Determination • If bridge 380 was to be closed and a farm was located at point A: • What is the detour distance from point A to point B? • Distance measured in Google Earth • Shortest detour length approximately 3 miles A B

7. Location of Structurally Deficient Bridges and Detour Length

8. Descriptive Analysis • Significant number of structurally deficient bridges had a detour of less than or equal to 2 miles • Most bridges were found to be steel followed by timber • 6 bridges had at least an 11 mile detour • Longest detour found was 20 miles in western Kansas

9. Analysis • Study assumptions • Rural roadway volume and the typical number of daily trips was unknown • 80/20 split cars and trucks • Estimated user and infrastructure costs • $0.60 per mile for a car • $1.00 per mile for a truck or farm implement • $150,000 estimated bridge replacement cost by KDOT • 75 year bridge lifespan • $2,000 per year assuming yearly maintenance and inspection costs

10. Study Results • Based on the stated assumptions a threshold was developed • It was found a bridge should be closed with an ADT less than 8 and detour length less than 9 miles • Increasing vehicle operating costs to the driver over the life of the bridge far outweighed the cost of a new bridge

11. Survey of Practice • An electronic survey was conducted in March 2012 • Sent to all 105 Kansas counties • 29 counties responded

12. Survey of Practice Q1. Has your jurisdiction ever closed a bridge on a low-volume roadway? • Saline County • Leavenworth County • Montgomery County • Sherman County • Generally a limited number or no bridges have been closed during their careers

13. Survey of Practice Q2. What criteria were used to determine that the bridges needed to be closed? • Saline County’s plan • Maintenance costs and traffic operations • If land-locked, repair the bridge • Low-water stream crossing is always an alternative • Bridge substructure condition

14. Survey of Practice Q3. Has your jurisdiction ever tried to close a bridge, but was unable to due to other reasons? • Local politics • Land owners requested to keep the bridge open • County commissioners did not want to make the tough call • Counties have worked with the Kansas Historical Society to keep a structurally deficient bridge open

15. Survey of Practice Q4. Does your jurisdiction have a standard cost to repair a structurally deficient or functionally obsolete or unsafe bridge on a low-volume road? • Most did not • Seven responses • $50 to $100 per square foot • $50,000 to $250,000 for typical bridge replacement

16. Survey of Practice Q5. Would your jurisdiction be interested in an electronic copy of the final report? • All of the counties responded “yes” Now available online or through the Kansas DOT library http://ntl.bts.gov/lib/47000/47000/47089/KS-13-1_Final.pdf

17. Discussion and Conclusions • A significant number of rural bridges in Midwest states are structurally deficient or functionally obsolete that are maintained by local jurisdictions • Repairing or replacing these bridges are expensive for counties with limited infrastructure budget • It was anticipated at the beginning of the study that a large number of bridges would be in the “close bridge” category • This study was designed as a complimentary information in which county commissioners can use to determine if a bridge should be close or kept open to traffic

18. Acknowledgements and Contact Information • Kansas Department of Transportation • Ron Seitz, Bureau of Local Projects Steven D. Schrock Associate Professor Department of Civil, Environmental and Architectural Engineering The University of Kansas 2159B Learned Hall, 1530 West 15th Street 785-864-3418 schrock@ku.edu