One of the forms this "madness" takes is setting off at the crack of dawn for some faraway place to set up an "ambush" --they lie in wait for some particular train to pass, then click the shutters of their cameras.
他們「瘋」火車的行徑包括一大早就去一個遠遠的地方「埋伏」，只為了守候某一班火車經過，趕快按下快門。