Yeah sounds like a bad design. Whether it was money issues witht he builder etc. that they did this. There are contractors that do this. Normally if i know that that would cause a problem with the customer, i split two zones, each on either side of the walkway. Some water misting over is unavoidable, but its not directly spraying. I dont know what time you water, but for best results you should start around 3 in the morning and finish before sunrise, so the lawn absorbs water, and it dried by the morning sun. As DR. Pete stated most people dont worry about sidewalks at 330 because no one is out. LEt me know what happens!
Thanks
Ray
Rays Above and Beyond Automatic Lawn Sprinklers