The complaint, filed as a request for declaratory and injunctive relief, asks the court to block Bow Mar from constructing the gates and seeks compensation. Denver and Littleton argue that Bow Mar, a small enclave of roughly 950 residents, does not have the authority to decide which roads are public or to restrict drivers from neighboring cities who use them.

At issue is Bow Mar's proposal to build gates at two of its three main entrances and to close a smaller entrance near Tufts Avenue. Town leaders say the measures are necessary to protect children, retirees and seniors from cut-through traffic. A traffic study cited by the town found that about 1,200 vehicles pass through the community daily, with a majority of drivers not living in Bow Mar.

The town has already introduced speed bumps, posted "kids at play" signs and lowered the speed limit to 20 mph in an effort to calm traffic, but residents have continued to raise safety concerns.

Denver Mayor Mike Johnston framed the lawsuit as a matter of ensuring residents get the services and access they pay for. "Bow Mar doesn't get to decide what is or isn't a public road, and they don't get to make life less safe for Denver and Littleton drivers," Johnston said in a statement. "As mayor, it's my responsibility to ensure residents receive the services they paid for, and we are ready to go to court – and if necessary, beyond – to ensure the roads stay open."

Littleton Mayor Kyle Schlachter said public roads should remain open to everyone in the region. "Public roads should serve the public, not become a tool for excluding people from their own community," Schlachter said. "I will continue to demand equal access for both Littleton and Denver residents who all share this regional network. We should be working together to find solutions – not erecting barriers that divide us."

According to the two cities, they have attempted for several months to engage Bow Mar in good faith. Among the alternatives they offered were targeted police enforcement against dangerous drivers and efforts to find other ways to reduce traffic through the town.

Bow Mar posted a statement online defending its position. "The Town's objective is not to exclude our neighbors or make travel unnecessarily difficult. It is to reduce unsafe traffic before a child, pedestrian, cyclist, driver, or resident is seriously injured," the statement read in part. "Every community has an obligation to respond when conditions on its streets create a legitimate safety concern. Bow Mar is no different. Emergency services, deliveries, guests, and visitors will continue to have access, and other primary entry points to our community will remain open."

The case now moves to court, where a judge will weigh whether Bow Mar's safety rationale justifies restricting access to roads that Denver and Littleton maintain are part of a shared public network. The outcome could set a precedent for how small municipalities across the region manage traffic and access on streets that connect to larger neighboring cities.