Sign Log Inspection Guidance March, 2013

1. Sign Log Inspection GuidanceMarch, 2013

2. Sign Log Inspection Guidance This PowerPoint is intended to provide visual examples and illustrations for sign log inspection expectations. This document will be upgraded periodically as more and better illustrations are acquired. It is important that sign inspectors review this document and MoDOT’s expectations at least once before beginning an inspection season. The night time images supplied in this document are intended for illustration purposes only; photograph is not a suitable tool to actually judge a sign’s performance.

3. Sign Log Inspection Guidance Sign log inspections serves several purpose: Verifies signs are installed and maintained where they were intended for safety and legal reasons Assurance field inventory for signs in up to date Identify sign maintenance work needed for the year It is the process MoDOT has chosen to meet federal retroreflectivity requirement

4. Sign Log Inspection Guidance In general, sign inspections are looking to verify the following: General appearance – is the appearance of the sign such that a private citizen might consider it to look good? Night time visibility – is the sign clearly visible in both legend and color at night and as seen from sufficient distance for the driver to make a decision and react? Sight Distance obstructions – is there anything blocking the view of the sign, such as trees or other vegetation, utilities poles or other signs? Installation - Is the sign plumb and facing the correct direction to function properly?

5. Sign Log Inspection Guidance Pictures Not only do these look bad in the public’s eyes, but more importantly they are not performing the job they were installed for

6. Obsolete Sign Types There are specific sign fabrication types that are considered very obsolete and need to be replaced. These sign types have not been in production for close to 15 years and typically used engineer grade sheeting that only had a 7 year life: Wood – typically D-boards found on two lane roadways Steel – identifiable by rust steaks on the face of the sign and/or signs that are painted on the back side Button Copy – button copy is sign legend made up of aluminum letters with reflective buttons inserted into them to make them reflect Any sign made with engineer grade sheeting – this sheeting is easily identified as it has no pattern in the sheeting

7. Obsolete Sign Types Steel Signs – Back side of signs were painted and now normally rusty – made with engineer grade sheeting. The sheeting on the face many times gets chalky and cracked. Button Copy - reflective buttons reflect as long as they are not broken, but backgrounds are typically engineer grade and no longer reflect

8. Type III High Intensity Glass Bead Pattern Engineer Grade No Pattern Obsolete Sign Types OK to leave in place until end of life Obsolete Replace Type IV High Intensity Prismatic Pattern Wood Signs – typically only used to make destination signs for two lane roadways and were produced using engineering grade sheeting (this example has never been in service – found in the sign shop) Current Standard

9. A new engineer grade sign isn’t as bright when it is new and lasts a much shorter period of time than the newer technologies. For these reasons and the fact we have not produced a sign with engineer grade sheeting for close to 15 years all such signs are far past their life expectancy and should all be replaced. Examples of Sign Sheeting Technology Improvements Side by side images of new signs Engineer Grade REPLACE ALL High Intensity Glass Bead LEAVE UNTIL END OF LIFE High Intensity Prismatic CURRENT STANDARD

10. As time has passed, sheeting technology has improved in both durability and in the amount of light the sheeting sends back to the driver, which relates to how bright the sign looks. These figures give you an idea of what sign sheeting looks like up close and how they work. Examples of Sign Sheeting Technology Improvements

11. Expectations for Sign Performance Minimum expectations for night time sign visibility and legibility are measured from the driver’s seat at operating speeds with low beam headlights. If signs do not meet these expectations the appropriate maintenance must be performed. Signs must be legible from an adequate distance for the driver to see and react to them. Legibility distance expectations are: Flat sheet signs must be visible from approximately 300ft Structural signs must be visible from approximately 600 feet Inspectors do not need to physically measure these distances, but must become familiar with what these approximate distances look like when inspecting signs. Visual cues, such as lane line skips (10ft skip / 30 foot gap), delineator spacing (typically 50 feet) roadside delineator posts (528 feet) or ERM (1056 feet) can be used to help an inspector learn what these distances look like visually

12. Expectations for Sign Performance Another judgment method if there is more than one sign visible at a time is to compare signs to one another. If a signs or delineators farther a way are brighter than the sign you are inspecting it is likely an indication that sign you are inspecting should be replaced. Notice how dark the speed limit sign is compared to the delineators, the black on white regulatory sign 800ft down the road and the curve sign 1200ft down the road. The speed limit sign should be the brightest sign being the closest to the driver

13. A Critical think to keep in mind when doing your inspections Now that we are only inspecting in half of the counties each year it is very important to remember that the sign you inspect this year will not be inspected again for two years Keep this in mind when inspecting a marginal sign, if it is close to falling below expectations this year it is very likely to be beyond failure when it is next inspected. Judge signs appropriately Expectations for Sign Performance

14. Expectations for Sign Posts Signs that are out of plumb to a degree that the driving public would notice this defect should be repaired or replaced Signs that are warp, twisted or otherwise not supporting the sign so it is oriented to the roadway properly should be repaired or replaced Post that are too short, should be replaced. The bottom of a sign in a rural location should be a minimum of 5 feet above the driving surface and 7 feet in urban areas. See EPG 903.3 for greater details No post should be shorter than 5 feet measured from the ground to the bottom of the sign with the exception of signs on I-beam posts. I-beam post shall not be shorter than 7 foot 9 inches measured from the ground to the bottom of the sign to meet federal crash standards Structural post sizes #3 up to #6 must be spaced a minimum of 7 feet part to meet federal crash standards

15. Expectations for Sign Posts Post are expected to be plumb with some tolerances allowed. Ask yourself, does it look obvious that the sign post is leaning? If so then it should be corrected. The warning sign with the 25 mph advisory speed plaque needs to be corrected compared to the reverse turn which is plumb. To place a number on this, if a posts is 1” or more per foot in length out of plumb it should be repaired.

16. When looking at a sign, imagine a vertical line or a straight post, compared to the actual post you are inspecting. Expectations for Sign Posts

17. Having signs properly oriented to traffic is critical. The sign could be brand new, but if not aimed properly may not be visible at all at night and in some case the day Expectations for Sign Posts

18. Correctness of Sign Installations As part of the inspection signs should also be looked at to assure they are correctly installed or are appropriate to the application

19. Just a few examples Incorrect installations can led to maintenance issues, safety issue or simply do not convey the message they were intended to properly This should be one post displaying a route N with one left/right arrow plaque A sign this wide should be on two post for support and safety Chevrons should be installed 4 feet above the driving surface, this one will we hidden as the grass grows higher All curve signs are to have an advisory speed plate

20. Nighttime Inspection Procedures Signs shall be inspected 1 hour after sunset and at least 1 hour prior to sunrise to ensure complete darkness Signs shall be inspected with low beam headlights Keep interior lights off so eyes are acclimated to darkness (dim lights are OK to illuminate computer keyboard) Once frost and/or dew begin to settle on the signs (affecting retroreflectivity), discontinue inspections Signs on side streets shall be inspected by driving the side street approaching the sign

21. Nighttime Inspection Procedures The sign legend and background colors must be visible at night as they are during the day (for example, a guide sign’s white legend should be clearly visible and the background should be recognizable as green, blue or brown). If not, replace the sign. If inspection takes place after leaves have dropped and tree limbs fall within the view of the sign, but do not obscure sign: trim limbs to account for the time when leaves will regrow Inspection vehicles should be typical cars, SUVs or pickups, 2002 or newer Two-person inspection crews for safety Inspection conducted from travel lane (not shoulder) and conducted at normal travel speed Headlights should be cleaned before inspection begins. Clouded or hazed lenses should be polished and headlights should be properly aimed

22. Headlamps The reason proper headlight adjustment is so critical is newer cars have cutoff head light patterns so light is much more tightly controlled. If headlights are aimed too low, for example, you may make signs bad that really are not. • Sealed Beam Pattern • Modern Cutoff Pattern – far less light is aimed at our signs so it is even more critical for our signs to be in good condition to reflect or be as bright as with the older headlights

23. Sign Failure Types There are many ways a sign can fail or not perform to expectations. The following images are just some examples of what can go wrong. Photographs are not legitimate means to evaluate a sign at night, however, the can be used to illustrate what to look for during a night time inspection.

24. An example of an engineer grade sign with type III high intensity glass bead sheeting. Sign background is green during the day (black at night) but during the day you can see the legend doesn’t look right, in reality, the sheeting used to form the letters is delaminating and will appear black at night as well, see the image in the next slide

25. All sheeting has a life expectancy. The green engineer grade sheeting still maintains its color, but typically fails by fading and no longer reflecting. The type III sheeting on the other hand tends to fail by eventually delaminating, which causes the loss of both the daytime appearance and night time reflectivity. These signs are far beyond the point of replacement

26. MoDOT has not manufactured Trapezoid signs for a very long time, most were made of engineer grade sheeting and are past their useful life Also be aware of illegal signs installed on our posts or on our right of way. The bottom sign is not a MoDOT sign, but was made and installed by a private citizen – notice the legend is much different compared to standard highway legend and the sign has square corners. This sign should be removed

27. Sign sheeting can be damaged very easily if not handled and stored correctly. You can see water damage on the top panel and pressure damage on the lower panel. Both these areas will be black at night and would warrant the replacement of the sign.

28. An example of an old button copy sign. With a camera flash you can see the letters still reflect, although some better than others. However, the green background, route shield and the warning sign below show no signs of having any retroreflection remaining. This sign need to be replaced.

29. Damage from fire arms and paint ball guns can effect the signs legibility and life expectancy. If portions of the legend or symbol are covered or destroyed or if areas of the sheeting are completely gone then the sign should be replaced

30. To meet federal safety standards, no I-beam post can be shorter than 7’9”. Other sign posts should be a minimum of 5’ measured from the ground to the bottom of the sign to be considered break a way

31. The inability to see signs an night may not always be a bad sign, but many times can be caused by where they are placed or what has grown in front of them

32. It is not possible to determine what signs will reflect at night during daylight conditions. The signs in the left image all look about the same condition, but clearly they are not when viewed at night. REPLACE

33. It is also critical that when a sign is marked for replacement the day time crews doing the sign work do not over ride the decision. Too many times a sign is bad at night, but the sign may look just fine during the day and is left n place. The street name sign looks bad day and night, but the one way sign looks just fine during the day when in reality it is the worst sign on the post at night.

34. Pictures do not do an accurate job of defining a bad or good sign, however, they can be used to help illustrate the point. If you look at what a new, or good sign looks like it can help you judge a poor sign. Compared side by side you can see how the left two speed limit signs are almost dead, the middle sign is marginal and while the right two signs is what is expected. While all signs appear to be bright, only the left sign really has the red background

35. A wide variety of stop sign various conditions. Only those in the green boxes would be considered good, in the yellow box is marginal and the remaining would fail due to color, retroreflectivity and/or damage to the sign face.

36. Sign retroreflectivity can be even more critical in urban areas to overcome other light sources

37. Visibility of signs is very critical at night, while traffic volumes are higher during the day, accident rates and fatalities tend to be higher at night. Signs are some of the few forms of guidance a driver can see at night so it is critical they are very visible.

38. There are many cues for the driver to follow during the day besides the chevrons: • guard rail • Trees • pavement However, at night most of these other cues are not available to drivers so signs become very critical to help motorist navigate so signs must be in good condition Retroreflectivity provides nighttime guidance

39. In the end Signs are not required by law, but are installed by engineering judgment to provide need. If the signs is legitimately needed it should be maintained to a level where it continues to provide the desired result … if it doesn’t then it becomes a liability instead of a benefit to the public and to MoDOT. Conducting consistent, honest inspections will ensure that signs meet the need of the department and the public and should result in a steady replacement cycle of signs each year instead of an overwhelming effort if signs are ignored for too long.