Under the GDL program, the first step (Phase I) toward achieving a full drivers license is obtaining the instruction permit. The GDL law applies to all applicants under 18 years of age. The program divides the process of obtaining a full drivers license into a number of steps, each one gradually preparing the teenager for responsible and safe driving. The Texas Graduated Drivers License (GDL) law was implemented to reduce the number of casualties that result from such accidents. These road accidents usually result from risk-taking behaviors and lack of driving experience. Many studies show that young drivers under 18 years of age are more likely to be involved in a traffic accident during their first year of driving. How to Request your Texas Driving Record.Online Texas Drivers Education for Teens.