Altum prepared a Preliminary Environmental Study (PES) Form and a subsequent IS/MND for a street improvement project along Highway 111, the major thoroughfare of the City of Indio’s commercial corridor. Altum was then subsequently contracted to prepare the PS&Es for the project. Project specifications including City of Indio, Standard Specifications for Public Works Construction (Greenbook), and Caltrans Specifications were used and referenced in the project specifications. Design survey work was provided along with the PS&Es.
The Highway 111 Street Improvements project was a street widening program from Madison Street to Rubidoux Street (approximately 8,800 lineal feet) that included survey and design for widening the existing street section from 2-lanes in each direction to 3-lanes in each direction. The proposed project improvements involved widening of Highway 111 from four to six lanes between Madison Street and Monroe Street (approximately 1.2 miles); updating all traffic signals; updating sidewalks, ramps, and driveways to current ADA standards; installing a center median east of Madison Street; Relocating utilities such as fire hydrants and utility meters; undergrounding overhead wires; placing 6.5 to 8 inches of asphalt concrete over a pulverized base; construct six to eight inches of curb and gutter; removing and replacing traffic signal loops; relocating and reconstructing a bus shelter; relocate existing traffic signal and signs; and improving drainage within construction of drywells and catch basins with a max depth of 30 feet. The project included pulverizing the entire street section and reusing the pulverized material as road base for the new improvements and paving the new street section from curb to curb.
As the project was partially funded by federal funds administered through Caltrans and the Coachella Valley Association of Governments (CVAG), all improvements were designed to stay within the current right-of-way. This presented the unique challenge of providing one (1) additional lane in each direction while maintaining pedestrian facilities and matching existing commercial driveways.
Occurring in a fully developed commercial area in an older part of the City of Indio, ADA access and connections to existing driveways and sidewalks were a challenge that was successfully met. The widening of the street section to provide the additional lanes resulted in design modifications to the existing street cross-section as well with existing grades of less than 0.3%.