In Texas, if you are not disqualified from firearm possession, Penal Code section 46.02 now allows you to lawfully carry a handgun 1) on your own premises or premises under your control; and 2) inside of or directly en route to a motor vehicle that is owned by you or under your control (so long as (A) the handgun is not in plain view (i.e. is concealed), (B) you are not engaged in criminal activity other than a Class C traffic misdemeanor and (C) you are not a member of a criminal street gang). “Premises”in the section includes real property and recreational vehicles that are used as living quarters.
This law expands the right of qualified citizens to carry in their cars and on their way to their cars. But, this law strictly requires that, while bearing arms, you not be committing any violation of the law outside of a class C traffic offense. DWI, carrying prescription medicine outside of a properly-labelled bottle, possessing marijuana, and even reckless driving can make you unlawfully carrying a weapon. A violation of this statute is a Class A misdemeanor (up to a year in jail and a $4,000 fine), but if committed on any premises licensed to sell alcoholic beverages it becomes a third degree felony (2-10 years, up to $10,000 fine). The law prohibits doing so intentionally knowingly or recklessly. Recklessly means that you are aware but consciously disregard a substantial and unjustifiable risk that the circumstances exist or the result will occur.
Additionally, there are places where carrying at all is still generally prohibited. Texas Penal Code section 46.03 lists numerous places, including the premises of school grounds or places school activities are being conducted, on the premises of a polling place on election day, on the premises of any government court or offices utilized by the court (without authorization), on the premises of a racetrack, in the secured area of an airport, or near a death penalty site on execution day. Violating this law recklessly is enough for a conviction. “Premises” in 46.03 means a building or portion of a building. It does not include any public or private driveway, street, sidewalk or walkway, parking lot, parking garage, or other parking area. Further, it is not a defense to 46.03 that you have a concealed handgun license. I would caution you that many municipal and county buildings hold court offices, and the statute can be prohibit to carrying at all in any such building (with exceptions). Additionally, carrying on any actual school property should be avoided due to current Federal law.