TRANSPORTATION ADVISORY BOARD AGENDA ITEM
ACTION REQUESTED:
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Receive the presentation and provide input on the proposed update to the City’s Road Improvement Plan
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DEPARTMENT: Transportation, Engineering and Development
SUBMITTED BY: Andy Hynes, PE, PTOE, Deputy City Engineer/Engineering Manager
BACKGROUND:
The City of Naperville maintains approximately 475 centerline miles of streets, including numerous arterial and collector roadways. Traffic flow and congestion on major roads has been a long-standing concern identified through past Community Surveys. Minimizing congestion on arterial roads and intersections also reduces travel times, lowers emissions, and reduces unnecessary traffic on neighborhood streets.
Between 1988 and 2008, the City of Naperville assessed a road impact fee. Acknowledging that the new development results in additional traffic on the city streets and that capacity improvements were needed to accommodate the additional traffic; the purpose of the fee was to assess developers for the proportionate share of the costs of the improvement of the arterial road system.
A key component of the impact fee process was the development of the Road Improvement Plan. This plan consists of a list of numerous road corridors and intersection capacity improvements needed to meet minimum level of service requirements within a 20-year timeframe accounting for future development and traffic growth. A detailed traffic model was developed to identify capacity deficiencies and new improvements. The projects included in the approved Road Improvement Plan were added to the City’s Capital Improvement Plan budget with many implemented over the past 15 years.
Since the impact fee program was discontinued in 2008 and the associated model is approaching the end of its 20-year traffic projection, an updated high-level analysis of current and projected traffic conditions on Naperville’s road network is needed. The updated Road Improvement Plan will identify the location of road and intersection capacity issues and the modifications needed to reach acceptable levels of service (vehicle delay and flow). These improvements will be incorporated into the City’s Capital Improvement Program as new projects to be evaluated in further detail.
In May 2024, the City hired Kimley Horn and Associates, Inc. to conduct a study to update the Road Improvement Plan. Over the past year, Kimley Horn worked with staff to collect traffic data, perform capacity analysis of intersections and corridors on the arterial road network, and gather public input. A summary of the technical analysis and public comments related to existing traffic conditions was presented at the May 5, 2025 Transportation Advisory Board meeting (File No 25-0507).
DISCUSSION:
At the July TAB meeting, Kimley-Horn will provide a presentation on 2050 traffic projections and discuss specific projects proposed for the City’s Road Improvement Plan update. A copy of the presentation slides is attached. Specific topics covered in the presentation include:
• 2050 Traffic Projection Methodology
Traffic growth rates for intersections and road segments were developed using a combination of historical traffic data, new developments, and traffic projection data provided by the Chicago Metropolitan Agency for Planning
• Road Improvement Assumptions
The traffic analysis assumes that various road improvements that are in progress or planned by the City or partner agencies will be completed prior to the 2050 analysis period. An example project is the widening of 248th Avenue between 95th Street and 103rd Street that is currently in the design engineering phase.
• 2050 Capacity Analysis
Using projected traffic conditions, capacity analysis for arterial and collector intersections and road segments were performed.
• Proposed Intersection and Segment Improvements
Preliminary capacity improvements needed to raise the 2050 projected traffic conditions at underperforming intersections and road segments to an acceptable level of service were identified.
• Potential Road Diet Locations
The study identified road segments that have excess capacity. These segments may be evaluated further with the Bicycle and Pedestrian Plan update for consideration of a road diet.
• Estimated Costs
A preliminary estimate of the cost to construct each of the intersection and road segment capacity modifications is provided.
• Next Steps
Considering the input received at the August meeting, a recommendation to approve the updated Road Improvement Plan will be presented at a future TAB meeting.