Don`t park past the white line painted along the street once those River Rail trolleys start running in Little Rock`s River Market district. River Rail officials ran tests Thursday during the day while cars lined the streets. Painters have put down white lines on streets that are on the trolley route so motorists know how much room they have. A relieved Central Transit Authority Official said the line painter painted a little close. The line gives a motorist a visual guide. Any part of a vehicle over the line could be blocking the path of the streetcars. Also Thursday the city installed caution signs to warn parkers that their vehicles will be towed if they are across the line. Motorists also have to be careful of their sideview mirrors. They might get snapped off if they`re over the line. Tests along the two point two mile line will continue for the rest of the month. Passenger service is to begin in Little Rock and North Little by November First but could begin as soon as mid-October.