Engineering Smarter Intersections in Loudoun County's Growing Transportation Network
Loudoun County, Virginia’s transformation over the past three decades has been nothing short of remarkable. When Gorove Slade began working there in the mid-1990s, Loudoun was still largely rural, with rolling farmland and historic towns defining its character. Between 2000 and 2024, the population rapidly grew from 169,599 residents to 447,837 residents, an increase of 164%.*
This remarkable transformation creates both opportunities and challenges for transportation infrastructure. As new developments emerge and traffic patterns evolve, ensuring safety and efficiency at increasingly busy intersections remains critical. At Gorove Slade, our comprehensive approach to intersection analysis ensures we deliver the optimal solution for each unique location and every person who passes through it.
Throughout Loudoun County’s transformation, we’ve contributed by designing more than 100 traffic signals as the road networks have expanded. Our expertise spans the full spectrum of intersection improvements—from traditional signalization to innovative intersection designs, roundabouts, and strategic turn lane configurations. This comprehensive understanding of intersection safety and traffic flow has become our hallmark in serving one of the nation’s most dynamic counties.
Algonkian-Lowes Island Boulevard Intersection Improvements
The Power of Integrated Planning: From Entitlement to Construction
Effective intersection design requires thorough analysis that considers multiple factors: existing and projected traffic volumes, crash history, operational efficiency, constraints from right-of-way and utilities, and long-term corridor impacts. Our systematic approach ensures each solution is tailored to the specific needs of the location and surrounding network.
Our advantage in Loudoun County stems from our unique position in the development ecosystem. Unlike consultants who only see projects at the design phase, Gorove Slade works with clients from the earliest entitlement stages through final construction. This comprehensive involvement allows us to anticipate design challenges and optimize solutions from the very beginning.
The Arcola Center development exemplifies this seamless approach. We supported the project through initial entitlement and traffic study work, prepared signal justification reports that led directly into signal design and guided the project during its multiphase implementation through permitting to final construction. This end-to-end involvement ensures consistency and efficiency that benefits both our clients and the traveling public.
At One Loudoun in Ashburn, our team carried out traffic engineering and planning services to support the 360-acre development and the surrounding transportation network. Since 2012, this work has included studies on traffic impact, intersection improvement, pedestrian safety, signal warrants, and traffic control, plus entitlement and signal design.
The Evergreen Mills Road improvements for Loudoun County Public School’s HS-14 site exemplify this integrated approach. As part of planning for the future high school, we provided comprehensive transportation planning that included initial due diligence studies, Traffic Impact Studies, Signal Justification Reports, and ultimately the design of three new or modified traffic signals.
Our analysis of the Evergreen Mills Road corridor from Ryan Road to Hartland Drive revealed the need for strategic phased improvements: widening from two to four lanes, turn lane improvements at multiple intersections, and a new signal at the school’s primary access point. Critically, we are working closely with the roadway design team to ensure that phased improvements at the Evergreen Mills Road/Red Hill Road/Ryan Road intersection would minimize future rework. This forward-thinking approach saves both time and taxpayer dollars.
Sometimes a Signal is Not the Best Solution
At the intersection of Route 15 and Lovettsville Road, initial recommendations called for signalization based on a previous corridor study. When Gorove Slade conducted the comprehensive Signal Justification Report, our analysis revealed that while a signal met Manual on Uniform Traffic Control Devices (MUTCD) warrants, the specific traffic patterns and corridor characteristics suggested that alternative improvements would better serve long-term safety and operational goals.
Working closely with Loudoun County’s Department of Transportation and Capital Infrastructure (DTCI) and Virginia Department of Transportation (VDOT) staff, we evaluated multiple alternatives, including roundabout configurations. Through collaborative analysis and data-driven evaluation, we identified strategic turn lane improvements that would provide enhanced safety while optimizing traffic flow.
Route 15 and Lovettsville Road Improvements
Navigating Complex Regulatory Requirements
One of the most challenging aspects of intersection improvement projects is navigating the complex regulatory requirements and review processes involving multiple agencies. Our deep relationships with Loudoun County and VDOT staff and our thorough understanding of review standards enable us to guide projects efficiently through approval processes.
Take, for example, the Lansdowne Boulevard and Woodridge Parkway Signal Justification Report. During our traffic analysis, VDOT requested that we recalculate our numbers using more stringent assumptions about how many drivers actually make right turns on red lights. We swiftly adjusted our study and resubmitted the updated analysis, which led to project approval. Ultimately, our analysis showed that the current four-way stop signs were working well and didn’t need to be replaced with a traffic signal.
When the community raised concerns about multiple vehicle collisions and speeding through the intersection at Algonkian Parkway and Lowes Island Boulevard, we worked with Loudoun County to develop design plans that were a complete solution that included converting single lanes to dual left-turn lanes, ADA-compliant improvements, signal modifications, and enhanced pavement markings. Working within budget and schedule constraints, we delivered construction plans for Loudoun County that directly addressed the safety issues while meeting all regulatory requirements.
Innovative Intersections and Network Maturity
As Loudoun County’s road network matures, we’re increasingly focused on “innovative intersections”—evaluating and designing solutions that maximize safety and efficiency within existing right-of-way constraints for all users, including pedestrians and cyclists. Our work on the Loudoun County Parkway/Claude Moore Signal Justification Report involved a rigorous evaluation of potentially feasible innovative intersections using VDOT’s Junction Screening Tool (VJust).
This forward-thinking approach is essential as the county shifts focus from basic network connectivity to completing pedestrian and bicycle networks while planning future transit opportunities. Each intersection improvement we design today must consider current traffic patterns and how it will integrate with the county’s long-term transportation vision.
Our Expertise Delivers Results
To each new project in Loudoun County, Gorove Slade brings our distinct combination of technical expertise, regulatory knowledge, and collaborative approach. We understand that every intersection has a unique context that requires analytical rigor to identify the optimal solution—whether that’s a traditional signal, an innovative intersection design, a roundabout, or strategic turn lane improvements.
Our track record speaks for itself: more than 15 years as part of Loudoun County Public Schools’ on-call team, current prime consultant status on the County’s Task Order Development Traffic Analysis Services, and successful completion of dozens of regional traffic engineering projects.
But beyond our technical credentials, we offer something equally valuable: peace of mind from working with a team that understands the bigger picture. When we recommend a solution, it’s not just engineered for today’s conditions: it’s designed to serve the community safely and efficiently for decades.
As Loudoun County grows and evolves, intersection safety will remain a critical component of transportation infrastructure planning. At Gorove Slade, we’re committed to ensuring that every intersection we touch becomes safer and smarter, contributing to a transportation network that serves residents, visitors, and businesses with the efficiency and safety they deserve.
For more information about Gorove Slade’s intersection design and traffic engineering services in Loudoun County, contact our transportation professionals, who are ready to help navigate your next project from concept to completion.
*Source: https://www.loudoun.gov/1913/Demographic-Estimates-Forecasts
