You can run them over as long as it isn't intentional. I read an article where a man went to prison for a long time for running over a desert tortoise intentionally. It causes big problems to prevent a species from "take" when habitat destruction is the cause of it's demise. I have searched many, many areas of the southwest for HLs. When you get out of fragmented developed areas, what you know, there are always HLs (proper time of day, season and rainfall required). I had about 10 people e-mail last year asking me what they could do to save some coast horned lizards. When I described the tedious procedures and my own personal negative experiences they all got discouraged and not one HL was saved, legally at least.