The reason that cracks often start on the edges of the automobile windshield chip repair is because the edges are the structurally weakest area. The frit is on the glass because it keeps the ultraviolet light from the sun away from the polyurethane seal that holds the windshield in the frame. Without the frit, the windshield would quickly start leaking or just pop out of the frame of the car.
Insurance companies are more susceptible to cover the windshield if it is on the driver's side or if it is a more intense crack because it is more important to get it done in that case. They do not want any obstructions of view in the line of vision for the driver.
Replacing a car's windshield can be quite a costly affair. An alternative could be to try to repair your windshield, although this will only be feasible for smaller cracks. For any large cracks, you'll have to replace your windshield. There is however a number of steps you could take to ensure that you find a good and cheap fix auto glass deal.
Now you have 3 options. You can pay out of pocket, you can have your insurance company cover the cost, or you can do the repair yourself. The cost out of pocket will vary from $30-$60, depending on the company you chose. Filing with insurance is easy because it is no cost to you, and the auto glass repair company deals with the paperwork. You can also attempt the repair yourself, but if you do not feel comfortable, i would suggest calling a professional. There is a good step by step windshield repair Instructable available, as well as other information online.
The hole in the adhesive disc should be pushed out and the paper backing has to be peeled off. The disc has to be centered over the area proposed to be repaired, press it on the windshield using a tab present on the disc facing upwards.
Windshield replacement can be very expensive, and you obviously want to be absolutely certain it is a necessity before doing so. If you can get by with a simple repair, go for it. If not, make sure you take your time and go with a company that will do a quality job. The windshield replacement could cost more upfront, but the long term benefits will be worth it.