Scarborough Route 1 Highway Improvement Project

Project Overview

The Town of Scarborough, in coordination with MaineDOT, is advancing a resiliency project to address recurring high tide and storm-related flooding along Route 1 where it crosses Scarborough Marsh. In addition to improving flood resilience, the project will evaluate a revised roadway configuration that enhances multimodal access, including accommodations for bicyclists and pedestrians.

Project Purpose
The purpose of this project is to strengthen transportation infrastructure to withstand the anticipated impacts of changing weather conditions. To achieve this, the design proposes elevating this section of Route 1 to more than four feet above the highest astronomical tide (HAT-the highest water level that can be predicted to occur at a specific location due to the gravitational pull of the moon), while also improving safety and accessibility for all roadway users.

Project Location & Limits
The proposed improvements begin approximately 0.39 miles northeast of Harlow Street and extend northeast approximately 1.2 miles to Southgate Road, for a total project length of approximately 1.0 mile.

Project Background

Since 2023, the Town of Scarborough and MaineDOT have been working collaboratively to develop a long-term solution to flooding along this critical corridor. A conceptual approach has been identified that includes:

• Raising the roadway approximately four feet above HAT 
• Replacing existing culverts with a 75-foot bridge spanning the Dunstan River

During early planning discussions, the Town requested that MaineDOT evaluate opportunities to incorporate bicycle and pedestrian facilities to improve accessibility and safety.

Existing Roadway Conditions

• Four 12-foot travel lanes 
  • Two northbound lanes
  • Two southbound lanes
• 6-foot shoulders  

Proposed Roadway Design (as identified through MaineDOT and Town of Scarborough staff collaboration)

• Three 12-foot travel lanes
  • One northbound lane 
  • Two southbound lanes 
• 10-foot multi-use path 
• 4-foot shoulders 

Due to environmental constraints within Scarborough Marsh, the roadway cannot be widened. Instead, the proposed design maintains the existing footprint by converting one northbound lane into a multi-use path.

Purpose of the Multi-Use Path

The addition of a multi-use path was requested by local officials and supported by regional transportation studies, as well as Scarborough’s Comprehensive Plan, all of which highlight the need for expanded active transportation options.
Community survey data also indicates strong public interest in adding bicycle and pedestrian facilities along Route 1. Given the scale of this project, including the bridge component, this represents a unique opportunity to introduce multimodal access in this location.

Project Constraints and Considerations

Scarborough Marsh is a highly sensitive environmental resource. MaineDOT is required to minimize impacts, which limits roadway expansion. Traffic modeling conducted by MaineDOT indicates that reducing one northbound lane is not expected to cause significant delays. However, modeling does not fully account for real-world driver behavior, prompting the need for field validation through a pilot project.

Traffic Modeling & Pilot Project

MaineDOT has completed traffic modeling for the proposed lane configuration. The next step is to implement a pilot (demonstration) project in collaboration with the Town of Scarborough to collect real-world data. 

Note: The multi-use path will not be constructed during the pilot. Bicyclists and pedestrians will continue to use existing shoulders during this period.

Purpose of the Pilot Project

The pilot project is intended to validate the proposed design under real-world conditions. It will:

• Compare modeled traffic performance with actual conditions
• Identify potential issues such as congestion, safety concerns, or driver confusion 
• Evaluate impacts to surrounding roadways and the environment 
• Collect measurable data (travel times, delays, safety indicators) 
• Increase public understanding through demonstration 

Pilot Project Information

Before advancing a final design, MaineDOT will evaluate the proposed configuration through a temporary lane closure during the summer of 2026. This timeframe represents peak seasonal traffic conditions, ensuring the design is tested under the most demanding circumstances. Traffic operations will be monitored before and during the pilot through traffic counts and field observations. Following the pilot, MaineDOT will analyze the data and provide recommendations for the Town Council and the public to consider as part of the next phase of the project.

What to Expect During the Pilot

• Temporary lane changes using striping, delineators, cones, and barriers
• Advance warning through message boards 
• Temporary changes to traffic patterns 
• Traffic monitoring equipment in place 
• Roadway restored to existing configuration after the pilot 

Pilot / Demonstration Schedule

• May 6th, 2026: Town Council workshop, 5:30pm
• May 29, 2026: Pilot package complete 
• June 1, 2026: 
• Variable message boards installed 
• Public outreach begins (media, website, social media) 
• June 15, 2026: Temporary traffic pattern implemented 
• August 10, 2026: Roadway returned to existing configuration 
• Date TBD: Data review by MaineDOT and the Town of Scarborough

Project Status & Funding
The project is currently supported by preliminary engineering funds to complete a Final Design Report. Funding for final design and construction has not yet been identified. MaineDOT will continue to pursue discretionary funding opportunities to advance the project..

Next Steps

The results of the pilot project will inform the Final Design Report and help determine whether the proposed roadway configuration should move forward. Findings will be shared with decision-makers and the public prior to advancing the project.