Transportation & Roadway Case Studies
Argyle Forest Boulevard Widening | Roadway & Bridge Design | Duval County, FL
CSI provided conceptual through final design services for the widening of Argyle Forest Boulevard — a 4.6-mile corridor expansion from a 2-lane to a 4-lane roadway in Duval County, Florida, delivered in two segments for the Jacksonville Transportation Authority (JTA).
A centerpiece of the project was the replacement of the existing two-lane bridge over McGirts Creek with twin bridges, each carrying two lanes of traffic and a shared-use path. The replacement structure features a continuous flat slab superstructure on concrete pile-supported bents, decorative lighting pedestals, and design accommodating a 100-year storm overtopping event. The project also included 1,097 LF of MSE wall design, a concrete box culvert extension, and an overflow weir.
Segment I (Blanding Blvd. to Westport Road — 2.6 miles) and Segment II (Westport Road to Bridge Creek Drive — 2.0 miles) both encompassed a comprehensive scope of multidisciplinary services.
Key Engineering Work:
Roadway widening from 2-lane to 4-lane (4.6 miles total)
Twin bridge replacement over McGirts Creek (AASHTO Type II)
Bridge hydraulics report and 100-year storm design
MSE wall and gravity wall design (1,097 LF)
Concrete box culvert design and extension
Floodplain compensation facility (FPC) design
Stormwater and drainage design
Permitting through SJRWMD and USACE
Eight JTA bus pullout designs
Traffic analysis, signalization, and lighting design
Signing & pavement marking plans
Landscape, geotechnical, water, sewer, and underground electrical design (JEA)
Environmental studies and construction cost estimates
Public involvement meetings with area homeowners
Project Details
Client: Jacksonville Transportation Authority (JTA)
Location: Duval County, FL
Services: Roadway Design | Bridge Design | Wall Design | Permitting | PD&E Study | Public Involvement
Project Engineers: Ali Najafi, PE | Christopher Morse, PE
Arlington Expressway at Bethelite | Bus Pull-Out & Sidewalk Design | Jacksonville, FL
CSI provided roadway and pedestrian infrastructure design services for a new JTA bus pull-out on the Arlington Expressway Northside Service Road in Jacksonville, Florida, delivered under a Local Agency Program (LAP) agreement with JTA and the Florida Department of Transportation (FDOT).
The project extended pedestrian connectivity by linking the existing sidewalk at the Bethelite facility to the existing sidewalk network at University Boulevard (SR 109) — improving multimodal access along the corridor.
Key Engineering Work:
Bus pull-out design (LAP project)
Roadway widening and drainage design
Gravity wall and structural wall design
Sidewalk design and pedestrian connectivity improvements
Signing, pavement marking, and traffic control plans
Lighting design
Geotechnical design and landscape plans
Surveying and utility relocation
Construction cost estimating and specifications
Utility coordination with JTA and FDOT
Project Details
Client: Jacksonville Transportation Authority (JTA)
Location: Jacksonville, FL
Services: Roadway Widening | Drainage Design | Wall Design | Lighting | Signing & Pavement Marking | Surveying | Utility Relocation
Project Engineers: Ali Najafi, PE | Khaled Ramadan, PE | Christopher Morse, PE | Fares Tannous, PE | Scott Grimes
SR 15 / US 17 Mill & Resurfacing | RRR Project | Clay County, FL
CSI provided roadway resurfacing, restoration, and rehabilitation (RRR) design services for SR 15 / US 17 from CR 220 to Creighton Road in Clay County, Florida — a Florida Department of Transportation (FDOT) project aimed at restoring this principal rural arterial to current safety and pavement standards.
Key challenges included deteriorated asphalt pavement, eroded roadway slopes, and undersized drainage infrastructure in a high-density residential corridor — requiring careful scheduling and direct coordination with area homeowners to manage daytime construction limitations.
Key Engineering Work:
Milling and resurfacing with Superpave Asphaltic Concrete pavement design
Inside shoulder widening
Replacement of non-functional side drains
Drainage structure and pipe rehabilitation
ADA-compliant curb cut ramp construction
Signal loop replacement
Signing and pavement markings
Traffic control plans
Utility coordination and construction cost estimates
Project Details
Client: Florida Department of Transportation (FDOT)
Location: Clay County, FL
Services: Roadway Design | RRR | Drainage | ADA Upgrades | Signing & Pavement Marking
Project Engineer: Ali Najafi, PE
SR 21 (Collins Road to 103rd Street) Mill & Resurfacing | RRR & Bus Lane Design | Jacksonville, FL
CSI delivered roadway resurfacing, restoration, and rehabilitation (RRR) design for SR 21 from Collins Road to 103rd Street in Jacksonville, Florida for the Florida Department of Transportation (FDOT) — incorporating a pilot JTA dedicated bus lane conversion within the urban segment.
A key design challenge was reconfiguring existing no-parking lanes (8.5 ft) into 10.5 ft dedicated bus lanes for the Jacksonville Transportation Authority, achieved by reducing vehicle lane widths from 12 ft to 11 ft — a precision lane balance requiring careful traffic analysis and agency coordination.
Key Engineering Work:
Milling and resurfacing with Superpave Asphaltic Concrete pavement design
Dedicated JTA bus lane conversion (urban segment)
Paved shoulder construction (rural segment)
Sidewalk construction (urban segment)
Non-functional side drain replacement and cross-drain end treatments
Roadside ditch and vegetation clearing
Signal loop replacement
Signing, pavement markings, and traffic control plans
Utility relocation and coordination
Construction cost estimates and specifications
Project Details
Client: Florida Department of Transportation (FDOT)
Location: Jacksonville, FL
Services: Milling & Resurfacing | Drainage | Bus Lane Design | Signing & Pavement Marking | Signal Loops | Specifications
Project Engineer: Ali Najafi, PE
Crescent City Multi-Use Trail | Trail Design & Pedestrian Safety | Crescent City, FL
CSI provided multi-use trail design and pedestrian safety improvement services for the City of Crescent City, Florida — a Putnam County project extending an existing trail network and improving bicycle and pedestrian connectivity along a corridor linking multiple intersections to US 17.
Facing community opposition to the originally proposed route's impact on heritage trees and residential streets, CSI developed an alternative design approach using FDOT/MUTCD-approved Shared Lane Markings (sharrows) — directing bicyclists to use the existing roadway while minimizing construction impact on the surrounding neighborhood.
Key Engineering Work:
Shared-use path and multi-use trail design
Sidewalk rehabilitation and ADA ramp installation
Shared Lane Marking (sharrow) design per FDOT/MUTCD standards
Signing and pavement marking plans
Maintenance of traffic (MOT) plans
Surveying
Public involvement and community engagement
Project Details
Client: Putnam County
Location: Crescent City, FL
Services: Multi-Use Trail Design | Sidewalk Rehabilitation | ADA Upgrades | Signing & Pavement Marking | Public Involvement
Project Engineer: Ali Najafi, PE
