PORTLAND, Maine — When Vera Mauro comes to a drive-thru, she’ll usually keep driving toward the window. Mauro is deaf and uses American Sign Language to communicate. She typically writes her order down on paper, but on Tuesday, her usual pattern didn’t work when she stopped for a drink at a Portland Dunkin'. “The woman didn't exactly see me, so I used the horn. Yet she ignored, texted on her phone and made another person's drink, and when she came back, I held up the order on the paper. She saw that I had it, gave me an attitude,” said...