There are no guard towers, or Checkpoint Charlies, or even walls. But scores of American cities, counties and metropolitan areas are being divided again — splitting apart families, neighbors and, most important, voters with similar interests and needs — as states engage in the once-a-decade process of drawing the lines of new Congressional districts.

And mayors and local officials in many places are none too happy about it.

Austin, a liberal island in Texas that has long been carved into multiple districts, would still be divided in three under a plan that was drawn up last week by a Texas court. In North Carolina, where Republicans drew maps that are expected to give them a big advantage, a lawsuit complained that one of the new districts seeps into pieces of 19 different counties and has so many twists and turns that its perimeter is 1,319 miles long.

Toledo was splintered into three Congressional districts in the map that Ohio Republicans passed this fall — to the dismay of its mayor, Michael P. Bell, who worried that his city’s clout in Washington would be diluted if its representatives had to weigh the competing needs of different areas.

“I think, for us, having one representative that’s going to carry our water would be more beneficial,” said Mr. Bell, an independent, adding that there was talk of replacing the recently passed map with a new one that would split the city into two districts. “We want to make sure that our issues are covered.”