Lane Width Reallocations Based on 5-Year Crash Data Richard C. Moeur, PE ADOT Traffic Design March 2007 edition

Flagstaff Business Route 40 is primary east-west arterial street in Flagstaff Also known as “Route 66” Was US 66 from 1920s-1980s Currently signed as Historic US 66 Currently owned & managed by ADOT Will transfer to City of Flagstaff in future

Crash Analysis Part of design exception analysis for two B-40 paving projects in Flagstaff Looked at all reported crashes from MP Jan 00 - Dec 04 (5 years) Bike-MV crashes make up nearly 25% of all reported crashes in corridor (75 out of 300+ total crashes)

Bike-MV Crashes By Type

Bike-MV Crash Severity

Findings 60% of bicycle-motor vehicle crashes involved wrong-way bicyclists 50% of crashes involved wrong-way sidewalk or path riding 63% of bike-MV crashes involved sidewalk or path bicyclists 34% on north sidewalk BNSF OP - E Flg 10% on south side path downtown - E Flg 19% on other sidewalks (Milton, W 66)

Findings Only 1 crash involved an overtaking motorist colliding with a cyclist traveling in the roadway Motorist cited for Only 1 fatal crash at B-40 onramp at East Flag TI Bicyclist at fault in 72% of crashes Only 15% resulting in citation

Hot Spots 6 bicycle-MV crashes at Milton / B-40 83% wrong way riding on sidewalk 6 bicycle-MV crashes at US 180 / B-40 83% sidewalk riding 8 bicycle-MV crashes at Enterprise / B % non-roadway cyclists 62% involving pathway users (south side) 75% involved wrong way riding

Critical Issues Wrong-way riding Bicyclist approaches conflict points from unseen and unexpected direction Sidewalk / path operation Perceived as safer, but has higher crash risk Bicyclists enter intersections unexpectedly

Sidewalk/Path Conflicts - Left Turn From Parallel Road

Sidewalk/Path Conflicts - Left Turn From Cross Road

Sidewalk/Path Conflicts - Right Turn From Cross Road

Critical Issues Low apparent percentage of bicyclists riding in roadway Outside lane widths not sharable per Drivers must change lanes to pass Bicyclists may be uncomfortable occupying lane Relatively high traffic volumes Speeds consistent with urban arterial apx. 40 MPH through much of corridor

Lane Widths AASHTO Green Book & ADOT Roadway Design Guide allow wide variety of lane widths 12 ft is ‘basic’ width But is “worst-case” situation for sharing Looks sharable, but really isn’t 10’ - 11’ are fully endorsed by AASHTO 14’ is minimum sharable width ARS requires 3 ft passing distance for bicyclists

Recommendations Discourage wrong-way riding Encourage on-street riding

Recommendations 60 ft roadway (plus 2’ curb & gutter each side) Old lane widths 2 x 12’ lanes each direction + 12’ TWLTL Revised lane widths 10’ TWLTL 11’ inside travel lanes 14’ sharable outside travel lanes

Existing Lane Configuration

Recommended Lane Width Adjustments

ADOT Bike Policy ADOT will allow bike lanes or other facilities on state highways However, ADOT requires local agency responsibility for bike- specific signs & markings No agreement reached on B-40 (yet…?)

Possible Bike Lane or Shoulder Configuration

Questions? Presentation can be downloaded from: pres/b40flag.ppt