Setting Speed Zones

Oregon Transportation Safety Conference

October 2019

How are speeds set in Oregon?Some by state statute

2

• 15 mph Alleys or Narrow residential roadways (less than 18’ wide)

• 20 mph Business district, school zones and on some residential roads.

• 25 mph Residential districts, public parks and ocean shores

• 55 mph Rural highways (and not posted elsewhere)

• 60 mph trucks on most interstates and some rural highways (65 mph on some interstates and rural highways)

• 65 mph Passenger vehicles, light trucks on interstate highways (70 mph on some Interstates)

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Local road authorities can set speeds on low volume local roads

Set Emergency and Temporary speed zones

How are Speeds set in Oregon?Some by Local Agencies

15 M

PH

20 M

PH

25 M

PH Need Investigation to Determine 55

 MPH

65 M

PH

70 M

PH

Statutory Statutory

*Designated may be any speed or if roadway does not meet statutory requirements

How are Speeds set in Oregon?Some by Designating Speeds (the alternative to Statutory)

Designated Speeds

Where statutory speeds don’t fit the road or the land uses

When the statutory speed is greater than is safe or reasonable

Requires Engineering Investigation of conditions

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Request Investigation & Recommendation

State Traffic-Roadway

Engineer Action

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Speed Zone Investigation

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Collected, compiled, analyzed:

Roadside characterTraffic mix & volume

Crash dataRoadway measurements

Travel Speeds

Concurrence on Local Jurisdiction's Roadways

State Traffic Roadway Engineer

Local Jurisdiction 

Concurs/or not

Option to take to SZRP

SZRP Makes final decision

Speed Zone Order

Does not concur

Reconsider

Concurs

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Speed Zone Review Panel

Representatives from City, County, Safety, Enforcement and ODOT

Hears disputed speed zone cases

Makes final decision on speed zones

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Objective process

Statewide consistency

Minimize Speed Variance

Local options

Investigate “the middle”

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Travel Speed directly impacts mobility (time of travel)

Travel Speed directly impacts Safety

New methodology -Our task is to set Reasonable and Safe Speeds

Speed setting practices are often political

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Mobility was the highest value, increasing travel speeds to get there faster

Roads were built to move motor vehicles more quickly

Where were we in the past?

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Local road authorities are desiring to slow speeds to meet community values

We have many other users besides motor vehicles now

Where are we going in the future?

Set Context based on Land Use

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Set Speeds for Context and Function

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Proposed Target Posted SpeedsContext > Urban 

Core/CBDUrban Mix Suburban

Commercial and Residential

Suburban Fringe

RoadwayClass

Arterial 20‐25Low

25‐30Med Low

30‐35Med High

35‐45High

Collector 20‐25Low

25‐30Med Low

25‐35Med

30‐40Med High

Local 20‐25Low

20‐25Low

25‐35Med 

25‐35Med

An alternative speed using 50th

percentile can be used if:• 50th percentile speed is more than 5

mph greater than range• Context is inconsistent• Limited Access Facility

Speed can vary 10 mph below 50th if:• Average Crash rate exceeds 1.5

times average for functional class• More than one F&A in 3 yrs• Meets definition of residence

district

Proposed Target Posted SpeedsContext >

Roadway

Rural Highways Rural Communities

State Highways or Non‐state Arterials

85th percentile+/‐5 mph

50th percentile +/‐5 mph

Non‐State collectors or locals

50th percentile +/‐5 mph

50th percentile +/‐5 mph

Rural Communities (unincorporated communities) - within 10 mph of 50th

percentile speed:• Urban character• Meets Business or Residence District• DLCD Unincorporated Community

State Highways or Arterial; and Non-arterial County Road.+/-10 mph if:• crash rate 1.5 times statewide • more than one F&A class• limited sight distance crashes

Why is considering other methods important?

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• Reduce Crashes (a small reduction in travel speed results in a reduction of severe crashes)

• Improve Comfort and Consideration of Active Modes

• Increase Community Livability

• Transitioning to a more context based method

Thank you!19

Active Trans Options

Reasonable and Safe

All Users

Compliance

Safety