In the United States, different states have different laws governing cracked windshields. In the state of California it is governed by the California Vehicle Code (CVC) Section 26710.
Elements of Section 26710
According to the California Department of Motor Vehicles (DMV) rule 26710 of the CVC, operation of a motor vehicle upon a highway is unlawful if the driver's vision is impaired to either the front or rear, due to the defective condition of the windshield or rear window or both.
If a cracked windshield leads to an inspection by an officer; the driver will be directed to fix the windshield to meet the requirements of Section 26710 within 48 hours.
You can also be arrested and get a notice to appear in court with satisfactory evidence that the windshield has been suitably repaired or replaced to conform to the law.
To Whom is Section 27610 Applicable?
According to Section 26700 of the CVC, rule 26710 is applicable to any public or private motor vehicle with a few exceptions. All passenger vehicles; trucks; buses; truck tractors; fire trucks, fire engines, or other fire apparatus; and husbandry implements are required to follow the dictates of Section 26710.
In addition to conforming to rule 26710, all noncommercial Class A vehicles should have "clear and undamaged windshields," as stated on the California DMV website.
Exceptions to Section 26710
According to section 26700 of the CVC, all motorcycles are exempt from conforming to rule 26710.
Any vehicle that didn't require a windshield at the time it was first sold or registered under the law of any state or foreign authority and has been issued ID plates in consistence with section 5004 is exempt from rule 26710.