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GoogleIn California, a FasTrak or other toll tag may go on the inside of the windshield at the center of the top edge, within a five-inch square. A dash cam that qualifies as a video event recorder may go in a seven-inch square in the lower corner farthest from the driver, a five-inch square in the lower corner nearest the driver outside the airbag deployment zone, or a five-inch square at the center of the top edge. A phone may be mounted only in one of the two lower corner squares, or on the dashboard or center console where it does not block the view of the road. Everything else on the glass is restricted by Vehicle Code section 26708.
These are statewide rules, so they apply the same way in Sacramento, Roseville, Folsom and the rest of California. This guide is written by Mavi Auto Glass, a locally owned mobile auto glass company based in Roseville that replaces windshields and calibrates the driver assistance camera that sits at the top of many windshields. It quotes the current Vehicle Code text, corrects two common mistakes and explains what to do with your devices when the windshield is replaced. It is general information, not legal advice.
What does California law say about objects on the windshield?
The default rule is that nothing goes on the windshield. Vehicle Code section 26708(a) says a person shall not drive with any object or material placed, displayed, installed, affixed or applied upon the windshield or side or rear windows, or with anything that obstructs or reduces the driver’s clear view. Subdivision (b) then lists the exceptions, and each device has its own (Vehicle Code 26708).
| Device | Where it may go on the windshield | Section |
|---|---|---|
| Toll tag such as FasTrak | Center of the top edge, inside, within a five-inch square | 26708(b)(11) |
| Dash cam that qualifies as a video event recorder | Seven-inch square in the lower corner farthest from the driver, five-inch square in the lower corner nearest the driver outside the airbag zone, or five-inch square at the center of the top edge | 26708(b)(13) |
| Portable GPS | Seven-inch square in the lower corner farthest from the driver, or five-inch square in the lower corner nearest the driver outside the airbag zone | 26708(b)(12) |
| Phone | Same corners as a GPS, or on the dashboard or center console without hindering the view | 23123.5(c) |
| Signs and stickers | Seven-inch square in the lower corner farthest from the driver, or five-inch square in the lower corner nearest the driver | 26708(b)(3) |
For the toll tag itself, Bay Area FasTrak’s customer handbook gives the preferred position as the center of the windshield behind the mirror, at least 2 inches from the top edge, with an alternate position in the lower left or right corner at least 2 inches from the side and the bottom. FasTrak also notes that vehicles with a metal oxide windshield, a flat vertical windshield or metal hanging over the windshield may need an exterior, license plate-mounted tag (Bay Area FasTrak).
Is a dash cam legal on a California windshield?
Yes, if it fits the legal definition and sits in one of the three permitted squares. Section 26708(b)(13) covers a video event recorder, which the law defines as a recorder that continuously records in a digital loop but saves video only when triggered by an unusual motion or crash, or when the driver operates it to monitor driving. The same paragraph adds conditions that are easy to miss.
- The vehicle must have a notice in a visible location stating that a passenger’s conversation may be recorded.
- The recorder may store no more than 30 seconds before and after a triggering event.
- The registered owner or lessee may disable the device, and the recorded data belongs to the owner or lessee.
- A camera mounted on the dashboard instead of the glass is not one of the windshield exceptions, but it must still not obstruct the driver’s clear view.
A camera that records and saves continuously may not match that definition, so check how yours works before you mount it on the glass.
Where can you put a phone mount on the windshield in California?
Only in the lower corners. Vehicle Code section 23123.5 allows a phone to be used by hand while driving only if it is mounted on the windshield the same way a portable GPS is mounted under section 26708(b)(12), or on the dashboard or center console in a way that does not hinder the view of the road. The top center of the windshield is not a permitted spot for a phone.
Even when the phone is mounted correctly, the driver may touch it only with a single swipe or tap to turn a feature on or off. The base fine is 20 dollars for a first offense and 50 dollars for each later one (Vehicle Code 23123.5).
What are the most common mistakes about windshield mounting zones?
Two mistakes show up often. The first is describing the zones as “five square inches” and “seven square inches.” The statute says a five-inch square and a seven-inch square, which are areas of 25 and 49 square inches, much larger than five or seven square inches.
The second is saying the top center is reserved only for toll tags. Section 26708(b)(13) also allows a qualifying video event recorder in a five-inch square at the center of the top edge. What the top center does not allow is a phone or a GPS.
Why does the top of the windshield matter for driver assistance?
Because on many newer vehicles the top center is also where the driver assistance camera looks through the glass. That camera supports features such as lane keeping and automatic emergency braking, and a device placed in front of it can block part of its view. Before mounting anything near the rearview mirror, check the owner’s manual for where the camera sits and keep the area in front of the lens clear.
When a windshield is replaced, the camera has to be aimed again. Mavi Auto Glass performs ADAS static and dynamic calibration with its own Autel equipment, in most cases in the same appointment as the windshield replacement, when the vehicle, location and conditions allow.
What should you do with your toll tag and dash cam during a windshield replacement?
Take them off before the appointment and put them back in a legal zone afterward. The old windshield is removed with everything attached to it, and adhesive mounts may need new adhesive or a new mount on the new glass. Here is how to handle it in 4 steps.
- Remove the devices: take off the toll tag, the dash cam and any phone mount, and keep their cables together.
- Note where they were: a quick photo of the old windshield helps you put each item back in the same legal square.
- Wait for the technician’s instructions: ask when it is safe to attach new mounts to the fresh glass.
- Reinstall in a legal zone: follow your toll agency’s instructions for the tag and the table above for the camera and phone.
Before you mount a device on your windshield
Measure the square before you stick anything to the glass, and check that nothing sits in front of the driver assistance camera or in the airbag deployment zone. Confirm that your dash cam saves video only on a trigger if you plan to mount it on the windshield, and post the recording notice. Keep the phone in a lower corner or on the dash, and follow your toll agency’s mounting instructions for the tag.
