Traffic signal to be installed at Mission and Lee. Motorists heading to and from Leawood City Park in the coming weeks are likely to notice a new traffic control installation in the area. The city of Leawood will be installing a new traffic signal at the intersection of Mission Road and Lee Boulevard, just a block south of I-435. The installation is a joint initiative by Leawood and Johnson County Wastewater, which is in the process of a massive $335 million expansion of its Tomahawk Creek Treatment Facility, which sits west of Leawood City Park. The signal is expected to be installed and made operational sometime this month.