When you pass any sign along a roadway, you realistically have less than 8 seconds to engage with the customer. In most cases, you will have less.
Therefore, a good way to utilize this moment with prospective customers is to point them to your other channels; places where they can engage for more than a couple seconds.
Regular communication on where they can find more information on you and your products and services can be helpful. Directing them to a social media account or website acts as a reminder and secondary call to action for your customer.
If you don’t have a website, you should. If you don’t have social media, you should. These marketing channels allow you to fully tell your story where time is abundant (relatively speaking). Hook them with your sign and funnel them to your other channels.