Gymgraf-Jim's Graphics

Time Speed and Distance Graph

Viewing Highway Billboards

The Facts

• The average number of passengers per vehicle is only 1.6
• This means a lot of cars will have only the driver.
• Therefore billboards need to target the driver to be effective.
• Most drivers see the billboards at a distance between 300 to 400 feet.
• Drivers need to look away from the billboard between 75 to 100 feet before passing the sign.
• Retention decreases as the number of words increase.
• 90 km/h = 82 feet/second
• 3 seconds at 90 km/h = 246 feet traveled

Look Away Point

While driving, the field of view for most people is about 10 degrees wide, this is why the driver will see the billboards 300 to 400 feet away. Drivers are looking forward more than left or right. As the driver moves closer to the billboard the side ways viewing angle increases. The angle will continue to increase until it becomes too great to comfortably look sideways while driving. I refer to this as the "Look Away Point".

The illustration, on the right, graphs the relationship of time and distance while passing a billboard. Using the average speed of 90 Km/h we will start our timer at the distance of 300 feet. About 3 seconds later the driver will be in the look away area on the graph.

The angled lines from the billboard to the travel lane shows that as the viewing distance decreases the viewing angle to the side increases. The sign will appear to move behind the mirror out of view.

This angle - range - look away point relationship should be included during the design process. When determining the effective reading range you should consider that there is a minimum range for viewers. Ignoring this can create the illusion of positive readability while working on the design.

Message Retention

• The time to read the message is short - 3 sec.
• More than 7 - 8 words will be hard to recall later.
• From the readability and retention stand point, it is better to have less words with larger font than more words which will require smaller font.
• Reducing font size to include more words will reduce the time before the look away point and lower the effectiveness of your sign. Your viewers will need to be closer to start reading and have less time to retain the message.
• More negative or white space makes text easier to read at a distance.

My general rules are the primary message text  must be clear 300'  from the billboard - with the lesser text readable no less than 100' from the billboard. This minimum, maximum distance will ensure that your message can be seen clearly by as many people as possible.

See my Billboard Layout Proofing Guide for more information.

Contact me today for your next outdoor sign.