HIGHLAND The state agency that operates five upstate New York bridges spanning the Hudson River plans to post advertising on its toll booths. The New York State Bridge Authority said ads began appearing in the front windows of bridge toll booths last week week. The authority says the hundreds of thousands of dollars in annual revenue the ads are expected to generate will go toward maintaining the bridges. Advertising for alcohol or tobacco are prohibited, as are political ads and those that may pose a dangerous distraction to drivers. The authority operates the Bear Mountain, Newburgh-Beacon, Mid-Hudson, Kingston-Rhinecliff and Rip Van Winkle bridges. The agency says the spans total more than 50 million vehicle crossings each year.