Do not Hack Electronic Road Signs after reading how to do it HERE

As the title suggests, do not attempt to conduct these law breaking misdemeanors even thou it might be fun to say

"Change lanes NOW"
"Call 911 NOW if you see someone on the phone"
"Honk if you're Horny"
"Please ignore this roadsign"

after the learning exactly how to do it from i-Hacked:

"How many times have you driven by an electronic road sign like one of these?

This is the ADDCO portable sign. Today, you see what is on the inside, and how they are programmed to display important information.

*** WARNING YOU SHOULD NEVER TAMPER WITH THESE SIGNS ***

1. The access panel on the sign is generally protected by a small lock, but often are left unprotected. Upon opening the access panel you can see the display electronics.

2. The black control pad is attached by a curly cord, with a keyboard on the face.

3. Programming is as simple as scrolling down the menu selection to "Instant Text". Type whatever you want to display, Hit Enter to submit. You can now either throw it up on the sign by selecting "Run w/out save" or you can add more pages to it by selecting "Add page"

** HACKER TIPS ** Should it will ask you for a password. Try "DOTS", the default password.

In all likelihood, the crew will not have changed it. However if they did, never fear. Hold "Control" and "Shift" and while holding, enter "DIPY". This will reset the sign and reset the password to "DOTS" in the process. You're in!"

Source: i-Hacked via Jalopnik