According to the Abilene Police Department, the main thing for citizens to consider here is whether the vehicle can be operated safely. The law specifies that no objects/materials can be placed upon the windshield that obstructs or reduces the operator's clear view. This is a subjective issue as it relates to cracks in a windshield.
Officer Doug Wrenn says, "The bottom line here is that we are not endorsing citizens take any chances for the sake of convenience. If visibility is impaired, to the extent of them not being able to operate the vehicle safely, they should find an alternate means of travel and have the vehicle towed to a place for repair."