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Traffic Sign Retroreflectivity Questions and Answers

Requirements

What are the sign retroreflectivity requirements?
Where can I learn more about sign retroreflectivity?
How do I make sense of the minimum sign retroreflectivity levels from MUTCD Table 2A-3 in the field?
Are the sign retroreflectivity minimums based on clean or dirty signs?

Training

Is training for sign retroreflectivity available?

Management and Assessment

How often do signs need to be reviewed?
Does scheduling a sign for replacement meet FHWA's minimum sign retroreflectivity requirements if there is a collision before the sign can be replaced?
How should my agency build a sign management program?
Where can I find software to manage my agency's signs?


Inspection Methods

Does the calibration sign, comparison panel, or the 60 year old inspector used to inspect a sign need to be present in the event of a court case?
What is the difference between regular headlamps and European headlamps?

What are the aiming specifications for vehicle headlamps?
Which of the five inspection methods should my agency use?
How much will each inspection method cost?
How much time will each inspection method take?
For the Control Signs Method, why do control signs need to be observed at the posted speed of the roadway?
Can I measure a stop sign for the required 3:1 white/red contrast ratio without a sign retroreflectometer? If so, how do I do so?

Do you have example signs that do not meet the minimum sign retroreflectivity levels?
For the Comparison Panel Method, when using comparison panels from 25 feet, why should I hold the flashlight near my ear?
How do I get rid of subjectivity?


Retroreflectometer

How much does a sign retroreflectometer cost?
Where can I find a sign retroreflectometer? 
Do I need to be certified to use a sign retroreflectometer?
Can you train me on how to use a sign retroreflectometer?


Funding

How do agencies receive funding for the management and maintenance of sign retroreflectivity?
Can federal safety funds (High Risk Rural Roads Highway Safety Improvement Program) be used to purchase a sign retroreflectometer?
Can federal safety funds (High Risk Rural Roads Highway Safety Improvement Program) be used to replace signs that do not meet minimum levels?

Other

What is the difference between bold and fine message signs?
What are other agencies in Washington State doing?
What are other agencies nationwide doing?




 
What are the sign retroreflectivity requirements?

The specific requirements are found in the 2009 edition of the 2009 Manual on Uniform Traffic Control Devices (with revisions 1 and 2 incorporated) (MUTCD) . Also see the FHWA Web page for more information.

 
Where can we learn more about sign retroreflectivity?

 
How do I make sense of the minimum sign retroreflectivity levels from MUTCD Table 2A-3 in the field?

This is one important reason why inspector training is necessary. Trained inspectors will not have to continuously refer to this table while conducting an inspection/assessment in the field. The Calibrated Signs Procedure nighttime visual inspection method accounts for these levels at the time when the inspector calibrates their eyes. Comparison Panels used for that type of nighttime visual inspection will also be at or near minimum levels. The Consistent Parameters Procedure uses the objective visual assessment of someone over the age of 60 and therefore the table is not necessary. Data collected using the Measured Retroreflectivity method can be evaluated in the office, or you design your inspection form to identify the requirements for a specific sign/color combination.

 
Are the sign retroreflectivity minimums based on clean or dirty signs?

There is no requirement that states the signs need to be clean. Some agencies clean their signs while other agencies inspect the signs in their current condition.

 
Is training for sign retroreflectivity available?

Yes. Sign up for the Local Technical Assistance Program (LTAP) Training ListServ to receive LTAP training announcements and updates by e-mail. They are sent a couple of times a month to inform you about classes, conferences, and other special events.

 
How often do signs need to be reviewed?

It is up to your jurisdiction based on how you plan to monitor/assess your sign inventory in accordance with your specific management plan. Once a year might be desirable, but if longer-lasting sheeting is used a longer assessment cycle could be acceptable. See the report " Methods for Maintaining Traffic Sign Retroreflectivity" for more discussion on managing your sign inventory.

 
Does scheduling a sign for replacement meet FHWA's minimum sign retroreflectivity requirements if there is a collision before the sign can be replaced?

Yes, a support statement found in Section 2A.08 of the 2009 edition of the MUTCD says: "Compliance with the above 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 with the above Standard even if there are some individual signs that do not meet the minimum retroreflectivity levels at a particular point in time."  

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How should my agency build a sign management program?

It is up to your agency to decide what works best for your situation. See the report "Methods for Maintaining Traffic Sign Retroreflectivity" on Sign Management Practices. Also, there is a pooled-fund study being conducted by the National Cooperative Highway Research Program (NCHRP) currently underway to collect and publish successful practices related to managing sign inventories. You can also discuss this question with other local agencies.

 
Where can we find software to manage our signs?

Local Programs Traffic Services has a list of software sources on our Traffic Sign Retroreflectivity Web page.

 
Does the calibration sign, comparison panel, or 60 year old inspector used to inspect a sign need to be present in the event of a court case?

We cannot answer this question since it would be up to the specifics of a case. We suggest that you consult with your attorneys regarding this question.

 
What is the difference between regular headlamps and European headlamps?

One important difference is that modern headlamps (including the European style) have a distinct "cutoff" to keep light from distracting oncoming motorists. Older, halogen style headlamps do not have this cutoff and more light can reach overhead signs.

 
What are the aiming specifications for vehicle headlamps?

The FHWA website lists a headlamp aiming procedure.

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Which of the five inspection methods should my agency use?

It is up to your agency to decide what works best for your situation. There is an interactive walk through in the FHWA Sign Retroreflectivity Toolkit that will give you a suggestion on which method may work for your situation. You may also discuss this with other local agencies.

 
How much will each inspection method cost?

This depends on many variables. There is no set answer. You can check with other local agencies.

 
How much time will each inspection method take?

This depends on many variables. There is no set answer. You can check with other local agencies.

 
For the Control Signs Method, why do control signs need to be observed at the posted speed of the roadway?

The Control Signs Method, using a Calibration Signs Nighttime Visual Inspection technique, or Consistent Parameters Visual Nighttime Inspection to monitor these control panels, then you would conduct your inspection at or near the posted speed of the roadway. This ensures you are viewing these signs under similar conditions to how all drivers observe these signs. 

 
Can I measure a stop sign for the required 3:1 white/red contrast ratio without a sign retroreflectometer? If so, how do I do so?

The only way to measure the contrast ratio, is to use a sign retroreflectometer. However, signs that do not meet the contrast ratio requirement should be obvious during an inspection. If necessary, a sign retroreflectometer could be used for confirmation. 

 
Do you have example signs that do not meet the minimum sign retroreflectivity levels?

Control signs that are at or approaching the minimum levels are likely to be available within your existing sign inventory. FHWA is also developing a "recipe" of how these control signs could be made from new materials overlaid with available films. Local Program Traffic Services has Comparison Panels that can be loaned out. Contact the Local Programs Engineering Services Specialist.

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For the Compaison Panel Method, when using comparison panels from 25 feet, why hold the flashlight near your ear?

With the flashlight next to your ear, the sign's retroreflectivity will be directed back toward the light source, which will be located at your eyes. So you need to have the flashlight near eye level and parallel with your line of sight to get a true measure of retroreflectivity.

 
How do we get rid of subjectivity?

All the methods were developed to avoid subjectivity. In the visual inspection methods, which are likely to be the most susceptible, the recommendations to calibrate the inspectors eyes before inspections or use comparison panels address this issue. However, it may be helpful to address subjectivity in your maintenance/assessment method. 

 
How much does a sign retroreflectometer cost?

They cost between $10,000 and $15,000, depending on the features each sign retroreflectometer has. Basic models cost approximately $8,500. Models equipped with Global Positioning System (GPS), barrcode readers, and Bluetooth range from $9,700 to $15,000.

 
Where can we find a sign retroreflectometer?

Your agency can borrow one from Local Programs Traffic Services. To do so, please contact the Engineering Services Specialist. Agencies might also be able to borrow one from a neighboring agency, rent one, or purchase one. Local Programs Traffic Services has a list of companies that rent and sell sign retroreflectometers on our Traffic Sign Retroreflectivity Web page.

 
Do I need to be certified to use a sign retroreflectometer?

No, certification is not required, but it is important that you use a sign retroreflectometer device in accordance with the manufacturer's instructions.

 
Can you train us on how to use a sign retroreflectometer?

Local Programs Traffic Services can train you on the use of our retroreflectometer, or a similar make and model. See our Traffic Sign Retroreflectivity Web page for information.

 
How do agencies receive funding for the management and maintenance of sign retroreflectivity?

Federal funds are typically not available for maintenance activities. However, there may be funding categories for which sign replacement is an eligible activity. However, it should be noted that many infrastructure needs compete for these funds. See FHWA's website for additional information on Federal funding. Contact the Local Programs Traffic Services Manager for more specific Federal-aid eligibility questions.

WSDOT provides no state funds for sign management and maintenance. Other state and regional agencies may know of other funds.

 
Can federal safety funds (High Risk Rural Roads or Highway Safety Improvement Program) be used to purchase a sign retroreflectometer?

No. 

 
Can federal safety funds (High Risk Rural Roads or Highway Safety Improvement Program) be used to replace signs that do not meet minimum levels?

Generally, High Risk Rural Roads and Highway Safety Improvement Program funds cannot be spent on maintenance activities. Therefore, these funds are not available to replace individual signs that do not meet minimum retroreflectivity levels. However, a larger sign evaluation and replacement project may qualify for these funds if tied to reducing fatal and serious injury collisions. Contact the Local Programs Traffic Services Manager for more specific Federal-aid eligibility questions.

 
What is the difference between bold and fine message signs?

Bold and fine designations refer to symbol signs. Signs that are considered bold symbol signs are listed in Table 2A-3 of the MUTCD. Others are considered fine symbol signs. Please refer to the 2009 MUTCD for more information.

 
What are other agencies in Washington State doing?

What are other agencies nationwide doing?

There is a pooled-fund study being conducted by the National Cooperative Highway Research Program (NCHRP) currently underway to collect and publish successful practices related to managing sign inventories. We will post the study on this Web page when it is available.

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