State Route 246 & Purisima Road Safety Improvement Project Paul Valadao, Caltrans District 5 April 22, 2009

1. State Route 246 & Purisima Road Safety Improvement Project Paul Valadao, Caltrans District 5 April 22, 2009 Lompoc City Hall

2. Purisima Project Purpose, Need, and Status State Route 246 & Purisima Road Safety Improvement Project • Need: Collision rate at intersection of Purisima Road and Hwy 246 is four times state average • Purpose: Project will eliminate potential of broadside collisions, and severity of collisions will decrease with lower speeds • Project is in the Environmental Phase

3. State Route 246 & Purisima Road Safety Improvement Project

4. State Route 246 & Purisima Road Safety Improvement Project Aerial view of Highway 246 and Purisima Road with Proposed Roundabout Design

5. Why a Roundabout and nota Signalized Intersection State Route 246 & Purisima Road Safety Improvement Project • Increase Safety • Increase Capacity / Reduce Delay • Accommodates Larger Vehicles • Less Maintenance • Reduce Vehicle Emissions

6. Roundabouts vs. Signalized Intersection State Route 246 & Purisima Road Safety Improvement Project Safety: Reduces Points of Conflict from 13 to 4 and Eliminates Crossing Conflicts Entirely

7. Roundabouts vs. Signalized Intersection State Route 246 & Purisima Road Safety Improvement Project In the 2008 Federal Highway Administration (FHWA) Study involving both transportation professionals and volunteers from the general public: • Roundabouts were chosen as one of nine proven safety countermeasures. • Of the nine, roundabouts were the only intersection safety countermeasure listed.

8. Reduce Number & Severity of Collisions State Route 246 & Purisima Road Safety Improvement Project In the 2007 National Cooperative Highway Research Program Report 572, 55 intersections throughout the U.S. were converted from a signalized or stop controlled intersection to a roundabout. Two years of collision data showed the following: • Number of collisions were reduced by 35% • Number of injury collisions were reduced by 76% • When compared to a suburban signalized intersection, the number of collisions were reduced by 67% • When compared to a rural two-way stop controlled intersection, the number of collisions were reduced by 87%

9. Reduce Vehicle Delay State Route 246 & Purisima Road Safety Improvement Project In the 2004 Kansas Department of Transportation Study, 11 intersections were converted from a signalized or stop controlled intersection to a roundabout: • Average vehicle delay was reduced by 65% • Average vehicle stops were reduced by 52%

10. Accommodates Larger Vehicles State Route 246 & Purisima Road Safety Improvement Project The geometry of a roundabout includes a truck apron that accommodates vehicles with large turning radii, such as buses, trucks, tractor trailers, farm equipment, and emergency vehicles.

11. Accommodates Larger Vehicles State Route 246 & Purisima Road Safety Improvement Project The proposed design will accommodate vehicles from the local area, farms, businesses and Vandenberg Air Force Base

12. Maintenance State Route 246 & Purisima Road Safety Improvement Project • Signals require continuous routine surveillance and inspection. • Signals require a human response when a suspected malfunction is reported. • When considering the landscape maintenance cost associated with a roundabout, the comparative lifetime maintenance cost for a signal is higher.

13. Reduce Vehicle Emissions State Route 246 & Purisima Road Safety Improvement Project In the 2004 Study of Roundabouts Across the U.S., roundabouts were shown to: • Reduce Carbon Monoxide Emissions by 32% • Reduce Nitrous Oxide Emissions by 34% • Reduce Carbon Dioxide Emissions by 37% • Reduce Hydrocarbon Emissions by 42% In the 2002 Study of Roundabouts Across the U.S., roundabouts were shown to: • Reduce Fuel Consumption by 30% Mandavilli, S.; Russell, E.R.; and Rys, M. 2004. Modern roundabouts in United States: an efficient intersection alternative for reducing vehicular emissions. Poster presentation at the 83rd Annual Meeting of the Transportation Research Board, Washington, DC. Várhelyi rhelyi, A. 2002. The effects of small roundabouts on emissions and fuel consumption: a case study. Transportation Research Part D: Transport and Environment 7:65-71.

14. Project Schedule and Cost State Route 246 & Purisima Road Safety Improvement Project The schedule for this project is: • Currently preparing Environmental Studies • Project Approval and Final Environmental Document (PA&ED): August 2009 • Ready to List (Project Out for Bid): April 2011 • Construction Complete: Spring 2013 The estimated capital cost for construction, right of way acquisition, and utility relocation is $3.5 million.

15. Comments and Questions State Route 246 & Purisima Road Safety Improvement Project • Ask the staff present at the Open House • Submit comments via comment card at the Open House • Submit comments by May 7, 2009 to Chief of the Environmental Planning Branch: Matt Fowler, Senior Environmental Planner Department of Transportation 50 Higuera St San Luis Obispo, CA 93401 or (805) 542-4603 or matt_fowler@dot.ca.gov

16. State Route 246 & Purisima Road Safety Improvement Project For More Information Project information posted on Caltrans District 5 website: http://www.dot.ca.gov/dist05/projects/ or contact Sara von Schwind Project Manager at (805) 549-3198 or sara_von_schwind@dot.ca.gov