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Thursday, September 10, 2015

Sign Effectiveness in 4 points

T.W. Forbes and R.S. Holmes in 1939's "Highway Research Board" Legibility Distance of Highway Destination Signs in relation to Letter Height, Letter Width and Reflectorization" proposed four general criteria that sign effectiveness could be measured by:

Pure Legibility - The distance at which a sign can be read given an extensive viewing time

Glance Legibility - The distance at which a sign can be read given a minimal amount of viewing time ( few seconds)

Priority Value - The Qualities of a sign than cause it to be seen and read first

Target Value - The characteristics which distinguish a sign from its background and other surroundings.

The more conspicuous a sign is from its background, the higher the likelihood of it being noticed and being effective. Factors that affect the conspicuity are: the observers field of vision, foreground complexity (too many distractions),sign border, font, form and shape recognition, intermittency of illumination, motion( swivelling or scrolling), colour, and the uniqueness of the signs features( i.e. shaped like a hot dog.)

So in order for a sign to stand out and be noticed, the four criteria Calibre Signs feel are necessary are:





Let's further break these criteria down with some examples.

Visibility: A signs needs to be clearly visible to achieve full impact. A sign should not be obstructed by other objects such as landscaping and trees. Calibre Signs looks out for these obstructions and will advise of potential problems. Sometimes objects cannot be removed and alternate suggestions need to be explored. Colour and contrast are vitally important so that the message is readable. For instance, having yellow lettering on a white background will not be of high contrast nor very visible. If the sign needs to be viewed at night, it should be illuminated, and or have reflective vinyl, otherwise it will be invisible. Atmospheric conditions may also affect a signs visibility such as snow cover, fog, or heavy rain. Sometimes ground signs are blocked by objects such as traffic, pedestrians or physical structures. It is more likely that a sign that is perpendicular to traffic will be more likely to be seen than a sign that is parallel to traffic (i.e. a storefront fascia sign). Sometimes small changes such as turning a flat wall sign into a protruding angled sign or a perpendicular sign such a pylon or hanging sidewalk sign- make help create sign awareness. The chart below show what researchers assess to be the minimum required legibility distances in varying situations:

Speed (MPH) With Lane change (in feet) Without Lane change (in feet)

25-30 410 155

35-45 550 185

45-50 680 220

55-60 720 265

>65 720 280

This is based on a perpendicular mounted sign. If it is a parallel mount sign, research shows that the sign needs to be 70% larger or it cannot be read in time. The next step would be determining the actual height required for the sign to be visible. Below is a chart demonstrating this:

Speed Limit Number of traffic lanes Sign Height(to top of sign face)

25 mph 2-4 12ft

35 mph 2-4 20ft

45 mph 2-4 35ft

55 mph 2-4 50ft

>Highway 75ft

At Calibre Signs we think that illumination is essential for most commercial signage. Aside from the 24hour advertisement of your business, it also helps increase visibility. Generally there are three basic means of signage illumination.

By lamps mounted outside oriented to shine on sign face

Internal illumination through sign's face

By illuminated elements such as exposed bulbs, LEDs or neon style tubing.

Legibility: Based on a person's "Cone of Vision" or Field of Vision, certain considerations come into play. Based on how far away the sign needs to be visible, the size of the letter font must follow accordingly - too small and it won't be noticed. Calibre Signs recommends that signs be designed with letters a minimum of 1" for every 25ft of distance. If a font is used that is difficult to read is used such as a "script font" or "tightly spaced" font- the message may be lost in readability time. Increase in letter height would be necessary when using cursive script font or letters with tight spacing etc. Colour contrast is required in order that the text stands out from the background.

Conspicuity: A sign needs space and time to be noticed. A sign that is hidden amongst a sign polluted environment will more than likely be missed and ignored. Observers need to "See the sign" in order to receive the message. Pylon signs can be very conspicuous because they usually stand high off the ground. To get noticed, a sign should contrast with its environment. A green sign with a forest in the background may get lost. Calibre Signs' graphic designers are experienced and will help recommend the best choice in making your sign stand out.

Readability: Using the criteria above, an observer needs to be able to assimilate all of the information presented and interpret and comprehend the message. Vertically lettered signs are usually more difficult to read than horizontally lettered signs. If the observer cannot read what the sign says the message is lost. The sign needs to make sense.

Calibre Signs takes your ideas and turns them into reality with knowledgeable and expert advice from proven sources and statistics. Signs are our business and we extend our expertise into making you a successful and lasting impression.


Posted by Stephanie at 11:47 AM
Edited on: Friday, June 16, 2017 12:32 PM