You need the following addons to use the SprintPay system:
Sprops
Wiremod
Advanced Duplicator 2

After subscribing to all the required addons, download the dupe file below:
SprintPay Github[github.com]

Open the zip file and copy the "garrysmod" folder to your "/steamapps/Garry's Mod" folder.

In the AdvDupe2 menu, you should see a folder called "sprint2" then a folder called "sprintpay" and inside it, a file called "sprint2_sprintpay_system".

Select it and make sure to select the checkbox "paste at original position".

Now spawn it and check the toll for a red rectangle area. This is the detection area for the chip you will install.

After pasting the dupe, you will see a Expression2 chip below the window of the booth of the red rectangular area, on both sides.

Using the wire tool, wire the inputs "Open" and "Close" to the respective expression2's outputs "Open" and "Close".

Repeat this steps with the other toll booth and you're done.

• At the entrance door of the toll booth, you will see a small ATM like contraption.
  
• Press "E" on the screen to spawn your card and weld it to your vehicle.
  
• You must weld it on your base/car. If you use the parent tool the card will not be detected by the system.

You're done!

Now pass your car through the SprintPay toll and it should open automagically.

Enjoy!