There is generally not a one size fits all solution for removing or changing the line painting in you parking lot. The considerations are Cost and available budget, the time allotted to the project, what type of paint we are trying to remove, is minor damage to the surface going to be an issue, what type of material are we removing the paint from (asphalt, concrete, urethane or epoxy coated flooring)
Here are the most common types in order and cost from lowest to highest cost. As well as common scenarios in brackets
Paint Out / Grey Out / Black Out: Covering paint with paint. This is done by using traffic paint which is the color of the surrounding surface such as black for asphalt or grey for concrete. (when low cost is paramount, temporary markings, over top of coated floors in garages and warehouses)
Asphalt Grinding: An asphalt grinder is a walk-behind machine that removes almost all paint types found on asphalt. The machine is typically used for removing lines from roads and highways. It removes all of the paint as well as up to a 1/4-inch depth of the asphalt’s surface. Ground surfaces visually blend in overtime but the scar will be there. (roadways, older asphalt, permanent solution with relatively low cost, concrete)
Sand Blasting / Dry Ice Blasting: A process in which sand, glass beads, or another medium is shot at high speeds through a machine across the surface of a hard material until it is smooth. Sandblasting is often done to remove a previous finish on an item, to remove rust, or to prepare a surface to receive a new coat of paint. The kind of medium used to blast the surface depends on how difficult the removal is and how much impact the material can withstand. (over concrete, metal and concrete curbs)
Pressure Washing w/ Chemical: Using a low-pressure washer (typically up to 3800 psi and can be heated or cooled with a chemical paint stripper) to remove paint from concrete with little to no surface damage. All water must be reclaimed when using this process as the waste water is highly toxic. (Airports, parking garages)
Shot Blasting: Shot blasting is the process of mechanically blasting concrete with tiny steel shots at a very high velocity. This process typically removes up to 3 ml of the concrete's surface to reveal a rough profile for improved bonding. The concrete dust is recovered by a powerful dust collection system leaving little to no mess or contaminants on the project. (warehouses and concrete, removing more durable coating like epoxy)