280 likes | 489 Views
Intersection Safety Analysis. Tualatin Valley Highway (Oregon Route 8) and SW Murray Boulevard Beaverton, Oregon Adrian Cantu Adam Larsen Nozomi Saito Zachary Horowitz. Presentation Outline. Introduction and Site Description Geometric Analysis Collision Data Analysis
E N D
Intersection Safety Analysis Tualatin Valley Highway (Oregon Route 8) and SW Murray Boulevard Beaverton, Oregon Adrian Cantu Adam Larsen Nozomi Saito Zachary Horowitz CE 510: Transportation Safety Analysis November 30, 2005
Presentation Outline • Introduction and Site Description • Geometric Analysis • Collision Data Analysis • Human Factors Analysis • Countermeasures • Cost / Benefit Evaluation • Proposed Actions / Conclusions / Next Steps CE 510: Transportation Safety Analysis November 30, 2005
Site Description - Overview Intersection of: Tualatin Valley Hwy (OR-8) Murray Boulevard Located in: City of Beaverton, Washington County, OR 8 miles SW of Portland Street Ownership: TV Hwy: Oregon DOT Murray: Washington County TV Highway Murray CE 510: Transportation Safety Analysis November 30, 2005
Site Description – Land Use • Toyota dealership - largest in Oregon • 2 gas stations • Shell • Arco (with AMPM mini-mart) • Convent / school • Nike and Tektronix located 1 mile north of intersection • Kmart CE 510: Transportation Safety Analysis November 30, 2005
Site Description - Geometry • Railroad tracks south of intersection • Pedestrian island on NW corner • 10° intersection skew CE 510: Transportation Safety Analysis November 30, 2005
Looking westbound on TV Highway CE 510: Transportation Safety Analysis November 30, 2005
Geometric Deficiencies • Driveways close to intersection • Long straights increase speed • Low median with old reflectors • No advance guide signs • Very small street signs • Bus stops close to intersection • 10° intersection skew • Railroad tracks • No streetlights on Murray north of intersection • Not enough storage in left turn pocket on Murray NB CE 510: Transportation Safety Analysis November 30, 2005
Western & Pacific railroad tracks with rubber surface CE 510: Transportation Safety Analysis November 30, 2005
Existing Crash Patterns Did not yield Right of Way: 65 Following too closely: 64 Rear-End Crashes: 115 Turning Movement: 81 CE 510: Transportation Safety Analysis November 30, 2005
Environmental Factors CE 510: Transportation Safety Analysis November 30, 2005
Crash Data: Time & Day of Week Afternoon peak (3 – 6 pm) on Friday is a bad time to drive… CE 510: Transportation Safety Analysis November 30, 2005
Crash Severity The total yearly safety cost is: $885,000 CE 510: Transportation Safety Analysis November 30, 2005
Collision Diagram Number of Total Crashes : 234 Crashes/year: 47 Crashes/MVMT: 9.7 Data sources: ODOT City of Beaverton CE 510: Transportation Safety Analysis November 30, 2005
Collision Location Analysis • Areas of Note: • Shell gas station driveway • Cut-through traffic • High rear-end crash locations • Arco gas station • AM-PM mini-mart • Tri-met bus 62 stop • Tri-met bus 62 stop CE 510: Transportation Safety Analysis November 30, 2005
Human Factors Analysis • Two site visits • Friday, November 25, 2005, 2pm • Sunday, November 27, 2005, 5pm • Drove through intersection on all approaches • Observed all corners & 100’ back of intersection • Spoke with locals • Toyota employees, Shell gas attendant, corner ‘sale sign’ person, Washington County Sheriff Deputy after traffic stop CE 510: Transportation Safety Analysis November 30, 2005
Human Factors Analysis • Driver comfort level is low • No advance warning of intersection • Substandard to other intersections in vicinity • Canyon/Hall, TV Hwy/153rd • Murray/Allen Murray/Jenkins • TV Hwy/Murray lacks mast arms, lane assignment markings, street signs, etc. • RR track parallel to TV Hwy • Crosswalk located to accommodate tracks CE 510: Transportation Safety Analysis November 30, 2005
Human Factors Analysis • No Bus Turnouts • No streetlights on SB Murray approach • Large grass field is an unusual corner feature CE 510: Transportation Safety Analysis November 30, 2005
Human Factors Analysis • High volumes • Minimal Signage at intersection • Poor visibility of street signs • No lane assignment (on roadway or overhead) • Two signals for three through lanes CE 510: Transportation Safety Analysis November 30, 2005
Countermeasures Proposed • Close or relocate driveways • Replace reflectors on existing median • Build/improve medians • Murray N of intersection • TV Hwy W of intersection • TV Hwy E of intersection CE 510: Transportation Safety Analysis November 30, 2005
Countermeasures Proposed • Add 2 street lights N of intersection on Murray. Replace bulb on SE corner • Add lights on the north side of TV Hwy on both approaches • Optimize clearance intervals http://www.symbolfactory.org/images/streetlights.jpg CE 510: Transportation Safety Analysis November 30, 2005
Countermeasures Proposed • Upgrade intersection signing, signal and markings • Advance guide signs • Overhead street signs • Lane use arrow marking • Intersection lane control signs • Mast arms • 3rd signal head on TV Hwy approaches CE 510: Transportation Safety Analysis November 30, 2005
Countermeasures Proposed • Delineate left turn paths • Lengthen left turn pocket on NB Murray http://www.tfhrc.gov/safety/pubs/04091/images/fig119.jpg CE 510: Transportation Safety Analysis November 30, 2005
Cost / Benefit Analysis • Yearly safety cost at intersection: $885,000 • A 10% CRF would save $88,500/year • Estimated costs of improvements: $150,000 • Assume 6% interest rate for 10 years • Calculate net present value • Benefit / cost ratio = 4.34 CE 510: Transportation Safety Analysis November 30, 2005
Proposed Actions • Improve intersection infrastructure to improve driver comfort and knowledge • Consider closing or realigning one or more of the service station driveways to reduce crashes • Repair light, improve median on TV Hwy • Review signal timing plan to see if changes can be made that to improvement safety • Figure out who is in charge of the intersection CE 510: Transportation Safety Analysis November 30, 2005
Conclusions • High volume intersection has both a high frequency and rate of crashes, low severity • Poor signage and appearance – affects driver comfort and performance • Odd geometry and land use mixes • Lack of ownership/accountability • Intersection should be on a priority list for further study / improvements – it is DUE CE 510: Transportation Safety Analysis November 30, 2005
Next Steps • Get additional volume, turn movement information • Crash reduction factors for countermeasures proposed • Get detailed improvement costs • Coordinate safety improvement plan with ODOT, Washington County, City of Beaverton CE 510: Transportation Safety Analysis November 30, 2005
Acknowledgements • Dr. Chris Monsere, PSU • Pam Maki, City of Beaverton • Bill Kloos, City of Portland • ODOT • Erin Wilson CE 510: Transportation Safety Analysis November 30, 2005
Questions and Comments CE 510: Transportation Safety Analysis November 30, 2005