Rich Crossler-Laird ODOT

Roadway Section

2010 ODOT Roadway Conference

Urban Design – Break Out Session

2010 ODOT Roadway Conference

Urban Design – Break Out Session

The Free For All Style of Urban Design

2010 ODOT Roadway Conference

Urban Design – Break Out Session

2010 ODOT Roadway Conference

Urban Design – Break Out SessionTopics• Urban Clear Zone vs. Lateral Offset• Status of the Roadside Design Guide Update in terms of

Urban Clear Zone• Summary and Recommendations of Recent Iowa State

and OSU Research on Urban Clear Zone/Lateral Offset • ADA – PROWAAC Special Report (2007)• Roundabouts

Klamath Falls

Pooled Fund Research Project with Kansas State University, 8 state DOTs, TranSoft Corp.

Lateral Offset to Obstruction

The lateral offset to obstruction is defined as the distance from the edge of traveled way, shoulder, or other designated point to a vertical roadside element.

Examples of these elements are curbs, walls, barriers, bridge piers, sign and signal supports, trees, and utility poles.

Lateral offset can be thought of as an operational offset where vertical roadside elements are offset to the extent that they do not affect a driver’s speed or lane position. Adequate clearance from these elements should be provided for mirrors on trucks and buses and for opening curbside doors where on-street parking is provided.

The adopted criteria specify a minimum operational offset for all roadway conditions and classifications of 1.5 feet.

Lateral Offset to Obstruction

ClarificationLateral offset should not be confused with the clear zone

Clear Zone - a clear recovery area, free of rigid obstacles and steep slopes, which allows vehicles that have run off the road to safely recover or come to a stop.

Lateral Offset - can be thought of as an operational offset, while the clear zone serves primarily as a substantive safety function.

Lateral Offset ?

If Nothing Else Can Be Done …

…Delineate.

Minimum Mitigation

Status of the Roadside Design

Guide Update

Status of the Roadside Design

Guide Update

AASHTO Subcommittee on Design July 19-23 2009

Indianapolis, Indiana

AASHTO Subcommittee on Design July 19-23 2009

Indianapolis, Indiana

Minimum Lateral Offset

vs.

Clear Zone

Minimum Lateral Offset

vs.

Clear Zone

9

Update ObjectivesUpdate Objectives

Updated RDG chapter for Urban Areas, including guidance on: clear zone – based on speed & volume – min. 10 ft (?) lateral offset (4-6 ft) landscaping (including median applications) sidewalk placement slope and ditch cross-sections sign supports utility pole placement traffic signals mailbox locations, business signs, etc.

Update ObjectivesUpdate Objectives

Urban rights-of-way are often extremely restricted, limiting the applicability of clear-zone practice – even in suburban-to-urban transitions.

Urban Chapter ObjectivesUrban Chapter Objectives

Urban Chapter Landscape Buffer (Planting Strip)

Configuration

Urban Chapter Landscape Buffer (Planting Strip)

Configuration

• NCHRP Project 22-17 – “Recommended Guidelines for Curbs and Curb-Barrier Combinations”

• NCHRP 22-19 “Aesthetic Concrete Barrier and Bridge Rail Designs”

• NCHRP 16-04 “Design Guidelines for Safe and Aesthetic Roadside Treatments in Urban Areas”

• NCHRP 22-18 “Crashworthy Work Zone Traffic Control Devices”

• NCHRP 20-7 (196) “Development of a Guide to Crashworthy Bridge Rail Systems”

• NCHRP 16-04 “Median Intersection Design for Rural High-Speed Divided Highways”

Research StudiesResearch Studies

• NCHRP Project 22-17 – “Recommended Guidelines for Curbs and Curb-Barrier Combinations” (Report 537)

• NCHRP Report 537 http://144.171.11.107/Main/Public/Blurbs/156147.aspx

• NCHRP 22-19 “Aesthetic Concrete Barrier and Bridge Rail Designs” (Report 554)

• NCHRP Report 554 http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_554.pdf

• NCHRP 16-04 “Design Guidelines for Safe and Aesthetic Roadside Treatments in Urban Areas” (Report 612, K. Dixon)

• http://www.contextsensitivesolutions.org/content/reading/safe_and_aesthetic_design_of_ur_/resources/safe_design_urban_roadside/

• NCHRP 20-7 (196) “Development of a Guide to Crashworthy Bridge Rail Systems” (Railings for Bicyclists)

• http://cms.transportation.org/sites/design/docs/Bike%20Rail%20Height,%20NCHRP%2020-7(168)%20Final%20Report.pdf

• Iowa State University “Clear Zone – a Synthesis of Practice and an Evaluation of the Benefits of Meeting the 10 ft. Clear Zone Goal on Urban Streets”

• http://www.intrans.iastate.edu/reports/clear_zone_report.pdf

Research Studies & Related ReportsResearch Studies & Related Reports

• Schedule for Adoption– Final chapter reviews and Technical

Committee balloting at September 2009 meeting in Delaware

– Ballot to SCOD in Fall 2009– TCRS to address SCOD ballot

comments, Sept 2010 (or sooner)– Ballot to SCOH in Fall 2010 (or sooner)

ScheduleSchedule

Current ResearchClear Zone – Lateral Offset

• Iowa State University, Tom Maze: “Clear Zone – a Synthesis of Practice and an Evaluation of the Benefits of Meeting the 10 ft. Clear Zone Goal on Urban Streets”

• Oregon State University, Karen Dixon: “Design Guidelines for Safe and Aesthetic Roadside Treatments in Urban Areas”

Iowa Study – Tom Maze

Minimum Setback – Distance to closest object to face of curb in study segment

Average Setback – Average distance between face of curb and all fixed objects in study segment

15th Percentile Setback – Offset distance that 85% of fixed objects are behind

Ex. - If 15th percentile setback is 6’ for a segment with 100 fixed objects, 85 of the 100 are offset greater than 6’ and 15 are less than 6’ from face of curb.

Segment Lengths of 15m were used for study purposes

Findings from Iowa Study – Tom MazeFindings from Iowa Study – Tom Maze

• For a segment, minimum, average, and 15th percentile setback distances do not have a statistically significant relation to fixed object crashes at the 90% confidence interval.

• Within 45 m of an intersection, roadways were found to have a statistically significant increase in the number of fixed object crashes at the 90% confidence interval.

• A consistent fixed object offset helps reduce the number of fixed object crashes.

• A weak relationship was found between the number of fixed object crashes and the posted speed limit on the roadway.

Findings from Iowa Study – Tom MazeFindings from Iowa Study – Tom Maze

• There is no significant relationship between the density of fixed objects and the number of fixed object crashes.

• When minimizing the number of fixed object crashes is a primary goal, a 5 ft clear zone is the most effective setback distance. (High linear relationship between setback distance and the number of fixed object crashes within 5 ft of the pavement edge.)

• When minimizing the cost of mitigating fixed object crashes is a primary goal, a 3 ft clear zone is the most effective setback distance.

• In the incremental cost analysis, the greatest benefits accrued when the setback distance was increased to 3 ft and to 5 ft from the curb.

“Safe and Aesthetic Roadside Treatments in Urban Areas”“Safe and Aesthetic Roadside Treatments in Urban Areas”

Dr. Karen Dixon – Oregon State UniversityMichael LieblerHong Zhu

Dr. Michael P. Hunter - Georgia Institute of TechnologyBerry Mattox

OBJECTIVES(1) design guidelines for safe and aesthetic roadside treatments in urban areas and(2) a toolbox of effective roadside treatments that

(a) balance pedestrian, bicyclist, and motorist safety and mobility and

(b) accommodate community values. The guidelines will be based on an evaluation of the effects of treatments such as trees, landscaping, and other roadside features on vehicle speed and overall safety. The

guidelines will generally focus on arterial and collector-type facilities in urban areas with speed limits between 25-50 mph.

NCHRP Report 612NCHRP Report 612

Evaluation of Pole, Light Standard & Post Crashes Urban Corridors - Weather

Evaluation of Pole, Light Standard & Post Crashes Urban Corridors - Weather

Weather

Speed Limit

Total 25 30 35 40 45 50 55

Dry 0 72 152 29 104 19 13 389

Wet 1 18 26 7 22 2 2 78

Ice 0 0 3 0 1 0 0 4

Fog 0 2 0 0 2 0 0 4

Snow 1 2 1 0 4 1 0 9

Other or Not Stated

1 8 6 2 2 0 0 19

Total 3 102 188 38 135 22 15 503

Karen Dixon – “Safe and Aesthetic Design of Urban Roadside Treatments”

Lateral Distance to Objects Hit - All Study CorridorsLateral Distance to Objects Hit - All Study Corridors

Lateral Dist. (ft.)

Speed Limit (mph)

Total PercentCumulative

Percent

25 30 35 40 45 50 55

0-1 0 35 71 2 19 1 1 129 25.6 25.6

1-2 2 29 44 16 50 13 3 157 31.2 56.8

2-4 0 26 32 2 32 2 3 97 19.3 76.1

4-6 1 6 23 8 18 1 0 57 11.3 87.4

6-8 0 3 11 1 11 0 0 26 5.2 92.6

8-10 0 3 4 3 2 4 2 18 3.6 96.2

10-15 0 0 0 3 2 0 6 11 2.2 98.4

15-20 0 0 3 3 1 1 0 8 1.6 100

Total 3 102 188 38 135 22 15 503 100

Karen Dixon – “Safe and Aesthetic Design of Urban Roadside Treatments”

Lateral Distance to Objects Hit – Curb Only CorridorLateral Distance to Objects Hit – Curb Only Corridor

Lateral Dist. (ft.)

Speed Limit (mph)

Total PercentCumulative

Percent

25 30 35 40 45 50 55

0-1 0 35 71 2 19 1 1 129 28.3 28.3

1-2 2 29 44 16 50 13 3 157 34.4 62.7

2-4 0 26 27 2 30 2 3 90 19.7 82.5

4-6 1 6 23 2 18 0 0 50 11.0 93.4

6-8 0 3 10 1 9 0 0 23 5.0 98.5

8-10 0 3 1 2 0 0 0 6 1.3 99.8

10-15 0 0 0 0 0 0 1 1 0.2 100

15-20 0 0 0 0 0 0 0 0 0.0 100

Total 3 102 176 25 126 16 8 456 100

Karen Dixon – “Safe and Aesthetic Design of Urban Roadside Treatments”

Merge/Acceleration/Drop/Bus Lane TapersMerge/Acceleration/Drop/Bus Lane Tapers

Objects at End of Merge Lanes or Downstream of Accesses More

Frequently Hit

Merge/Acceleration/Drop/Bus Lane TapersMerge/Acceleration/Drop/Bus Lane Tapers

Findings:• Frequent crashes when object located within 6’ of

roadway edge at taper points• Crashes more common at taper point even when objects

located > 6’ from roadway edge, but in line with lane that is ending

• Objects hit most often when within 20’ longitudinally of taper point

• Recommendation:

Establish buffer zone around taper that

should remain object free

Americans With Disabilities Act - aka: ADA

• US Access Board• Access to the Public Way• Public Rights-of-Way Access Advisory Committee

or PROWAAC

Americans With Disabilities Act - aka: ADA

Curb RampsUnder the ADA, an alteration to a sidewalk or street will give rise to an additional obligation to include curb ramps in the scope of the project. From the Title II regulation:

35.151(e)(2)

Curb Ramps. (1) Newly constructed or altered streets, roads, and highways must contain curb ramps or other sloped areas at any intersection having curbs or other barriers to entry from a street level pedestrian walkway. Newly constructed or altered street level pedestrian walkways must contain curb ramps or other sloped areas at intersections to streets, roads, or highways.

ADA Title II implementing regulations require that each part of a facility altered by, on behalf of, or for the use of a public entity after January 26, 1992, be designed and constructed so that the altered parts are readily accessible to and usable by individuals with disabilities to the maximum extent feasible.

Maximum Extent Feasible…

(c) To the maximum extent feasible.The phrase “to the maximum extent feasible,’’ as used in this section, applies to the occasional case where the nature of an existing facility makes it virtually impossible to comply fully with applicable accessibility standards through a planned alteration.

In these circumstances, the alteration shall provide the maximum physical accessibility feasible.

Any altered features of the facility that can be made accessible shall be made accessible.

If providing accessibility in conformance with this section to individuals with certain disabilities (e.g., those who use wheelchairs) would not be feasible, the facility shall be made accessible to persons with other types of disabilities (e.g., those who use crutches, those who have impaired vision or hearing, or those who have other impairments).

Maximum Extent Feasible

PROWAAC Special ReportAccessible Public Rights-of-Way

Planning and Design for Alterations

Provides Guidance for Projects in the

Public Right-of-Way

ITE Website http://www.ite.org/accessible/PROWAAC/

PROWAAC_SpecialReport.pdf

US Access Board Websitehttp://www.access-board.gov/prowac/alterations/guide.pdf

Downloadable pdf Full Version

Downloadable pdf Full Version (With Chapter Links)

Common Problems in Alterations That Cause Poor Installation

Drainage

Level Landing

Grade

Some Installations are Not Easy, But We Need to Find Reasonable Solutions

Before

After

Ramp Extends Parallel to Make Elevation and Grade

RoundaboutsWhat has ODOT Been doing?

RoundaboutsWhat has ODOT Been doing?

• Tech. Services Compiled Analysis and Report on the Astoria Roundabout• Ed Fischer formed a “Roundabout Taskforce” to look at ODOT

Roundabout Policy for Revision and Update• Re-writing the Roundabout sections of the Highway Design Manual and

Traffic Manual to Contain the Same Language and Encourage Equal Analysis When Considering What Intersection Control to Construct

• Investigating Roundabout Design Elements in Relation to Truck Operation Through Roundabouts

• Participating in an FHWA, AASHTO, TRB “Pooled-fund Research” project with 7 other state DOTs, Kansas State U. and TranSoft to look at Overweight/Oversize Trucks and Roundabouts

• Technical Services and Region 4 are Analyzing a Roundabout as the Preferred Option for Intersection Control southeast of Klamath Falls at the Junction of the Klamath-Lakeview Hwy and the Klamath-Malin Hwy

Evaluating Design Criteria for ImprovedEvaluating Design Criteria for Improved Access by Large Vehicles Access by Large Vehicles

Evaluating Design Criteria for ImprovedEvaluating Design Criteria for Improved Access by Large Vehicles Access by Large Vehicles

Evaluating Design Criteria for ImprovedEvaluating Design Criteria for Improved Access by Large Vehicles Access by Large Vehicles

Evaluating Design Criteria for ImprovedEvaluating Design Criteria for Improved Access by Large Vehicles Access by Large Vehicles

Proposed Roundabout for Proposed Roundabout for Klamath FallsKlamath Falls

Proposed Roundabout for Proposed Roundabout for Klamath FallsKlamath Falls

Oversize Vehicle Movements Oversize Vehicle Movements

Oversize Vehicle Entry Apron

Apron

Black – Oversize Vehicle

Red – WB-67

Pooled Fund Research Project with Kansas State U. Oversize/Overweight Trucks in

Roundabouts

Kansas: 1999 – 433 OS/OW Loads 2007 – 6,402 OS/OW Loads

Participants: Kansas State U. – Lead, Colorado, Connecticut, Iowa, Kansas, Mississippi, Ohio, Oregon, Washington, Wisconsin, TranSoft Corp.

Length – 249 ft. Weight – 681,600 lbs.

Length – 249 ft. Weight – 681,600 lbs.

Kansas Rt. 47 – Feb. 2010

Questions?Questions?