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Retroreflectivity What is it and Why Should I Care? Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009
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Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Dec 23, 2015

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Page 1: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

RetroreflectivityWhat is it and Why Should I

Care?

Matheu J. Carter, P.E.T2 Engineer

Delaware T2 Center

October 15, 2009

Page 2: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Delaware T2 CenterT2 Centers or LTAPs located in all 50 statesFunded by FHWA and state DOTsMission – promote training, tech transfer, research implementation at local levelDelaware T2 hosted by University of Delaware, part of Delaware Center for Transportation

Page 3: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Matt CarterCurrently, Delaware T2 Engineer, Municipal Engineering Circuit Rider, Safety Circuit RiderProfessional Engineer, licensed in six states20+ year career, civil & env engineering

Bridge, road, utility construction Design consulting Public sector (Director, DPW, Cecil County, MD)

Page 4: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

OutlineWhat is retroreflectivity?What is the MUTCD and to whom does it apply?What is the origin of the retroreflectivity standards?What are the standards?What do you need to do and when?What are your options for compliance?What should you be doing now?Why should you take it seriously?

Page 5: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

CautionThis is a big topicWhile a good start, this 2-hour webinar alone won’t prepare youSo where else can you turn?

The November 5 APWA CLL will be a big help also FHWA, APWA, ATSSA, NACE, and others have great web

content LTAP or T2 Centers in each state and tribal region – many

are conducting local training in your area

Page 6: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

So, what is retroreflectivity?And what is it not?

It is the ability of a material to return light back towards its sourceIt is not mirror-reflectivity, which bounces light off in the opposite directionIt is definitely not diffuse reflection, which scatters the light source – think of a painted wall

Page 7: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

So, what is retroreflectivity?These signs have varying retroreflective levels – notice how brightly one returns the light versus the others

Which of the stop signs below do you want at the intersections as your teenage child or grandparent comes home on a rainy night?

Page 8: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Manual on Uniform Traffic Control Devices

The MUTCD is the national standard for all traffic control devices installed on all roads that are open to public travelApplies to TCDs on “any street, highway, or bicycle trail open to public travel” – 23 CFR Part 655 Subpart FMany states have their own MUTCD that meets or exceeds the federal manual

Page 9: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Origin of retroreflectivity standardsGeneral retroreflectivity standards have existed in the MUTCD for some time – Section 2A.081993 DOT appropriations act required standardsMinimum retroreflective requirements established in Revision 2 of the 2003 Edition – Section 2A.09Minimum requirements resulted from research targeted at the reduced reaction times and vision of some older drivers – this becomes important with some of the compliance methods

Page 10: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

The standards – Table 2A-3

Page 11: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

The standards – Table 2A-3Sheeting types

Beaded (Engineer Grade, Super Engineer Grade, High Intensity)

Prismatic (High Intensity Prismatic, Diamond Grade, etc.)Examples

End Detour (black on orange) – orange ≥ 50 Do Not Enter sign (white on red) – white ≥ 35; red ≥ 7 and

contrast of white to red ≥ 3:1 (wash out concern)

Page 12: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Exempt signsParking/Standing/StoppingWalking/HitchhikingAdopt-A-HighwayBlue or Brown BackgroundsExclusive Use of Bikes

or Pedestrians

Note: Must still meet otherrequirements in MUTCD(inspections, retroreflective,etc.)

Page 13: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

What to do and when?Develop and implement a method or methods

“Compliance with the…Standard is achieved by having a method in place and using the method to maintain the minimum levels established in Table 2A-3. Provided that an assessment or management method is being used, an agency or official having jurisdiction would be in compliance…even if there are some individual signs that do not meet the minimum retroreflectivity levels at a particular point in time.” Section 2A.09

Effective date of Final Rule – January 22, 20081st compliance deadline– January 2012 (4 yrs)2nd compliance deadline – January 2015 (7 yrs)3rd compliance deadline – January 2018 (10 yrs)

Page 14: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

What to do and when?January 2012

Implementation & continued use of an assessment or management method designed to maintain retroreflectivity at or above established minimum retro levels (Table 2A-3)

January 2015 replacement of regulatory, warning, and ground-mounted

guide (except street name) signs identified as failing to meet the minimum retro levels

January 2018 replacement of street name signs and overhead guide signs

identified as failing to meet the established minimum levels.

Page 15: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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The methodsVisual Nighttime Inspection

Calibration Signs Comparison Panels Consistent

Parameters Measured Sign Retro

Expected Sign LifeBlanket ReplacementControl SignsFuture Method Based On Engineering StudyCombination Of Any

Page 16: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Visual nighttime inspectionTrained inspectorVisual inspection/assessment at nightNeed to tie to minimum values by using

Calibration signs procedure, or Comparison panels procedure, or Consistent parameter procedure

Page 17: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Visual nighttime inspectionCommon elements of all visual assessment techniques

Properly aim inspection vehicle headlamps http://www.automedia.com/Aiming_Headlights/ccr20010801ha/1 http://www.coolbulbs.com/HID-VISUAL-HEADLIGHT-AIMING-PROCEDURE.pdf

Two-person crew works best Having an inventory in advance is ideal Have evaluation form and criteria Conduct evaluations at roadway speed Use low-beam headlamps

Page 18: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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You “calibrate” your eyes with calibration signs Calibration signs

are near minimum retro

You then evaluate signs as compared to calibration signs

Calibration signs

Page 19: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Comparison panelsTie to minimum values with comparison panels

Panels are near desired retro Clipped to sign - viewed from distance Evaluate signs compared to panels

Page 20: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Uses parameters consistent with those used to develop the minimum levels

Inspector – older driver (60+) SUV type vehicle Cutoff headlamps

(properly aimed)

Consistent parameters

Page 21: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Visual nighttime inspections

Method advantages: Low administrative and fiscal burden Signs are viewed in their natural surroundings Low level of sign replacement and sign waste

Method disadvantages: Subjective … but research has shown that trained

observers can reasonably and repeatedly detect signs with marginal retroreflectivity.

Exposure/risk of conducting nighttime inspections Paying overtime

Page 22: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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The methodsVisual Nighttime Inspection

Calibration Signs Comparison Panels Consistent

Parameters Measured Sign Retro

Expected Sign LifeBlanket ReplacementControl SignsFuture Method Based On Engineering StudyCombination Of Any

Page 23: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Measured sign retroreflectivityUse a portable instrumentReceive proper trainingHave a protocol for consistencyCompare readings to minimum values

Page 24: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Measured sign retroreflectivityAdvantages:

Provides the most direct means of monitoring the maintained retroreflectivity levels

Removes subjectivityDisadvantages:

Cost of instruments (approx $10,000 to $12,000) Measuring all signs in a jurisdiction can be time

consuming Using retroreflectivity as the only indicator of whether or

not a sign should be replaced may end up neglecting other attributes of the sign's overall appearance.

Page 25: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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The methodsVisual Nighttime Inspection

Calibration Signs Comparison Panels Consistent

Parameters Measured Sign Retro

Expected Sign LifeBlanket ReplacementControl SignsFuture Method Based On Engineering StudyCombination Of Any

Page 26: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Expected sign lifeFind the life of the sheeting type in your areaReplacement based on expected life for individual signs

Page 27: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Expected sign life•Build and use a weathering rack like the one shown•AASHTO-NTPEP data•Sheeting company warranty information•Specify sign life•Measure existing signs with known install date and compare to min level

•Use weathering data or nearby jurisdiction’s weathering data

Page 28: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Blanket replacementAll signs in an area/corridor are replaced at the same time at specified intervalsSpecified intervals could be set based on expected sign lifeSome existing blanket sign replacement policies exist using 10-12 years for Beaded High-Intensity sheeting signs

City of Tempe, AZ Maintenance Zones

Page 29: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Control signsSign life is estimated using a subset of signs representing an agency’s inventory.

Subset of signs constitutes the “control signs” Control signs can be in-service signs or signs in a maintenance yard.Agency monitors control signs to estimate condition of all their signs.Periodically measure retroreflectivity of control signs.

Example of Control Signs

Page 30: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Other options

Flexibility is provided for future advancements in technology and methods that have not been fully developed (must be based on an engineering study)Combination of methods, also

Page 31: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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The methodsVisual Nighttime Inspection

Calibration Signs Comparison Panels Consistent

Parameters Measured Sign Retro

Expected Sign LifeBlanket ReplacementControl Signs

Future Method Based On Engineering Study

Combination Of Any

Page 32: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

What should you be doing now?Begin/update sign inventoryConsider which maintenance/management method(s) best for your agency (at least for now)Develop an SOP, policy memo, ordinance, etc. to establish the method(s) you will useTraining for you and staff/colleaguesBegin preparing budget authorities

Page 33: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Why take all this seriously?Will there be a federal or state Sign Inspector coming around? Don’t believe so.Must federally funded projects comply? Yep.Can this make a big difference in traffic safety for your residents and visitors? You bet.Will this be fodder for plaintiff’s lawyers, both legitimately and illegitimately? Most likely.

Page 34: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Why take all this seriously?Because it matters

Page 35: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Why take all this seriously?Because it matters

Page 36: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Why take all this seriously?Because it matters

Page 37: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Why take all this seriously?Because it matters

Page 38: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

Why take all this seriously?Because it matters

Page 39: Matheu J. Carter, P.E. T 2 Engineer Delaware T 2 Center October 15, 2009.

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Need more info or training?Contact your local LTAP or T2 Center and/or your local FHWA division office

Typical workshop training available Overview Workshop Inspector Workshop

Delaware T2 Center Matt Carter, T2 Engineer

[email protected]; (302) 831-7236