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

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

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)

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?

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

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

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?

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

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

The standards – Table 2A-3

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)

12

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.)

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)

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.

15

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

16

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

17

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

http://www.automedia.com/Aiming_Headlights/ccr20010801ha/1

http://www.coolbulbs.com/HID-VISUAL-HEADLIGHT-AIMING-PROCEDURE.pdf

18

You “calibrate” your eyes with calibration signs Calibration signs

are near minimum retro

You then evaluate signs as compared to calibration signs

Calibration signs

19

Comparison panelsTie to minimum values with comparison panels

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

20

Uses parameters consistent with those used to develop the minimum levels

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

(properly aimed)

Consistent parameters

21

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

22





23

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

24

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.

25





26

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

27

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

28

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

29

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

30

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

31




Expected Sign LifeBlanket ReplacementControl Signs

Future Method Based On Engineering Study

Combination Of Any

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

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.

Why take all this seriously?Because it matters





39

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

mailto:[email protected]

Documents

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