South Carolina Case Study: 

Systematic Intersection Improvements 

Cover Photo Credits: Mike Farmer, 3M Corporation 

http://safety.fhwa.dot.gov 

FHWA Safety Program
 

 

 

 

Introduction 

In 2007, the South Carolina Department of Transportation (SCDOT) and 

its safety partners defined the State’s “Road Map to Safety” in its formal 

Strategic Highway Safety Plan (SHSP). The goal was to reduce fatalities 

on South Carolina’s roadways to fewer than 784 by 2010, a 25 percent 

decrease from 2004. A secondary goal was to lower the number of trafficrelated injuries by 3 percent. The SHSP identified 5 key Emphasis Areas and 

24 specific targets to be addressed based on an extensive analysis of traffic 

crash data. Intersections were identified as one of nine target areas within 

the Serious Crash Type Emphasis Area. 

Photo Credit: Joey Riddle, South Carolina Department of Transportation 

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South Carolina Case Study: Systematic Intersection Improvements
 

Background 

In 2008, as part of the FHWA’s Office of Safety Intersection Focus State Initiative and consistent 

with the goals of the SHSP, SCDOT began identifying safety improvements to be deployed 

systematically at intersections across the State to reduce the number of fatalities and serious 

injuries. SCDOT identified more than 2,200 intersections for improvement in the South Carolina 

Intersection Safety Implementation Plan (ISIP). 

The first phase of construction began in September 2009, and approximately 1,280 intersections 

have been improved to date, primarily through signing, pavement markings, and signal 

enhancements. SCDOT is currently in the third phase of the plan and expects completion by 

early 2013. 

Intersection Selection 

The foundation of the ISIP is a 5-year analysis of statewide crash data, stratified into six different 

categories of intersections: signalized, single-lane stop-controlled, or multilane stop-controlled 

intersections in rural areas and signalized, single-lane stop-controlled, or multilane stopcontrolled intersections in urban areas. It was not necessary to differentiate ownership (e.g., 

State vs. local) since most of the roads in South Carolina are under SCDOT jurisdiction and 

nearly 95 percent of roadway fatalities occur on State-maintained roads. This analysis revealed 

that 44 percent of all intersection crashes occurred at 1.3 percent of the intersections in the 

State, based on a per-intersection threshold of five or more crashes within the 5-year period. A 

list of 2,204 candidate sites was developed based on these findings and included a variety of 

intersection types and locations. 

Overview of Systematic Improvements 

In response to the SHSP emphasis area goal of reducing fatal and serious injury crashes at 

intersections, those locations appearing within the ISIP were targeted to receive improvements 

in the form of updated signing, pavement markings, and signal enhancements. In order 

to address the 2,204 intersections, SCDOT established a streamlined installation process for 

making modifications using low-cost treatments. SCDOT followed FHWA’s Intersection Safety 

Implementation Plan Process to develop their systematic plan. 

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Types of Treatments 

SCDOT’s systematic improvements at stop-controlled and signalized intersections were 

primarily related to signing and pavement markings. Additionally, signalized intersections 

were treated with low-cost improvements specifically related to traffic signals and associated 

infrastructure. The typical improvements applied are listed below by treatment category. 

All Intersections 

• Signing: 

– Doubled up (left and right) signing 

– Oversized signing with high-intensity
 

fluorescent sheeting
 

– Advance Street Name signs (W16-8) on
 

Intersection Warning signs
 

– Retroreflective sign post panels 

– Solar–powered, sign-mounted beacons 

– Replacement of additional safety related
 

signs (e.g., Do Not Enter, One Way, etc.)
 

within 500 feet of the intersection
 

• Pavement Markings: 

– Properly placed stop bars (4’-8’ offset and
 

perpendicular to the mainline)
 

– Dashed edge lines to delineate the
 

mainline and turn bays and establish
 

points of conflicting traffic
 

– Lane arrows and word messages in
 

accordance with standard drawings,
 

general notes and specifications
 

– Addition of crosswalks 

Photo Credit: Joey Riddle, South Carolina Department of Transportation 

Photo Credit: Joey Riddle, South Carolina Department of Transportation 

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South Carolina Case Study: Systematic Intersection Improvements
 

Signalized Intersections 

• One signal head per lane 

• Supplemental nearside sign heads 

• Backplates with retroreflective borders 

• 12” LED signal indications 

• Pedestrian treatments such as push button indicators and pedestrian countdown signals 

Additional information on each of these treatments can be found in FHWA’s “Low-Cost Safety 

Enhancements for Stop-Controlled and Signalized Intersections.”3 

Photo Credit: Mike Farmer, 3M Corporation 

SCDOT provided one general template drawing for each of the four intersection types (signalized, 

four-way stop-controlled, two-way stop-controlled, and T-type stop-controlled) in the bid 

documents. Figures 1 through 4 show the typical application of these improvements to each 

specific intersection type. The templates were intended to provide general information to potential 

bidders about the treatments required by intersection type. 

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Figure 1. SCDOT’s Template for Signalized Intersection 

Figure 2. SCDOT’s Template for Four-Way, Stop Controlled Intersections 

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South Carolina Case Study: Systematic Intersection Improvements
 

Figure 3. SCDOT’s Template for Two-Way, Stop Controlled Intersections 

Figure 4. SCDOT’s Template for T-Type, Stop Controlled Intersections 

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Contracting for Systematic Intersection Improvements 

Following the identification of intersections through the development of the ISIP, SCDOT developed 

a contract vehicle structured to accommodate the systematic approach proposed in the ISIP. The 

contract was a single, statewide, 3-year contract that was renewable each year. It was structured 

to treat approximately one-third of the intersections identified in the plan each year for 3 years. 

Improvements to traffic signals were addressed through four separate, low-bid contracts that 

SCDOT let for bid. Four different contractors installed the low-cost improvements at the signalized 

intersections. 

For the signing and pavement marking enhancements, SCDOT chose to use a statewide, low-bid 

contract vehicle versus several smaller contracts for several key reasons: 

• Uniformity of implementation statewide; 

• Administrative efficiencies of a single contract; and 

• Economies of scale realized through lower unit pricing on larger-scale statewide contract. 

SCDOT chose not to use in-house maintenance staff on the project due to the magnitude of the 

project and the time it would take to complete. 

Stakeholders 

There were four primary stakeholders with roles 

in crafting the improvement plan, funding the 

improvements, and installing the treatments: 

SCDOT Headquarters; SCDOT District Offices; 

the contractor and subcontractor; and FHWA’s 

Office of Safety, Resource Center, and SCDivision Office. 

The four primary SCDOT Headquarters offices 

involved in this project were the Construction, 

Maintenance,Traffic Safety, and Contracts 

departments. SCDOT is a centralized 

organization where Headquarters controls 

funding and identifies projects, with input 

from the Districts. SCDOT has seven District 

Offices, each with a District Traffic Engineer, 

who coordinated with the contractor and 

SCDOT Headquarters on improvements to 

intersections within their District lines. 

The contractor selected by SCDOT was 

responsible for ground-mounted signs 

and pavement marking installations 

at all intersections within the project. 

The contractor’s engineering services 

subcontractor was responsible for staking all 

of the intersections, verifying the drawings 

matched field conditions, and making other 

professional engineering recommendations 

and decisions on behalf of the contractor. 

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South Carolina Case Study: Systematic Intersection Improvements
 

FHWA’s Resource Center and SC-Division Office 

provided training to SCDOT on systematic 

improvement concepts, signing and marking 

practices, and Highway Safety Improvement 

program (HSIP) eligibility requirements. 

Funding Process 

A section in the SCDOT SHSP identifies five key 

emphasis areas based on an analysis of crash 

data. One key emphasis area is Serious Crash 

Types, of which Intersections were one of nine 

crash types identified. Engineering strategies 

identified in the SHSP that address serious 

intersection crashes were also identified in 

SCDOT’s ISIP. The consistency between the ISIP 

and SHSP and the identification of the projects 

through a systematic, data-driven process 

allowed for the projects to be implemented 

using HSIP funds. Signing and pavement 

markings were two of several specific 

treatments proposed in the ISIP. USC 120(c) 

allows certain safety improvements such as 

signing and markings to be eligible for 100 

percent Federal funding; therefore, SCDOT’s 

3-year systematic intersection improvement 

project did not require any State matching 

funds. The project was included in SCDOT’s 

State Transportation Improvement Program 

(STIP). The approval of the STIP by SCDOT’s 

Commission allowed for the allocation of 

Federal appropriations. 

Contract Execution and Administration 

The SCDOT Offices of Traffic Engineering, 

Maintenance, and Construction coordinated 

with the Contracting Office to prepare the 

contract for bid. The low-bid contract was 

eventually administered at the Headquarters 

level through the Construction Office, with the 

Traffic Safety Office filling the role of project 

management. 

The contract was awarded to the lowest 

pre-qualified bidder. Prequalification of an 

SCDOT contractor is based on a verified 

experience and responsibility record and 

availability of equipment. The contractor 

selected was responsible for installing groundmounted signs and pavement markings at 

all intersections within the project areas. The 

engineering services subcontractor was 

responsible for ensuring that signing and 

pavement marking plans were tailored to the 

site conditions present at each intersection 

and met both State standards and MUTCD 

requirements, staking the intersections, 

and adjusting and submitting detailed 

construction plans on behalf of the contractor 

following the award of the low-bid contract. 

Under a separate contract vehicle, four 

other contractors supported this effort and 

were responsible for installation of traffic 

signal-related countermeasures at signalized 

intersections under this project. 

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Implementation 

SCDOT Headquarters released work orders to the District Traffic Engineering Offices, with 40 to 50 

intersections per work order (for a total of 45 work orders in the project). Most work orders comprised 

intersections within a single District to minimize coordination complexity across District lines. 

During the first year of the contract, SCDOT 

Headquarters created site-specific drawings 

for all intersections during the pre-construction 

development of work orders. During years 2 and 

3, SCDOT hired four independent consultants 

from a pre-qualified engineering services 

contract to develop site-specific drawings. Sitespecific drawings were developed from initial 

field inspections (year 1 by SCDOT, years 2 and 

3 by consultants) and provided to the contractor and subcontractor. Before beginning construction 

on a given intersection, the subcontractor identified and staked proposed intersections for new 

signs and pavement markings, verified that specifications within tolerances were met using the 

initial drawings, and if not, made layout adjustments as necessary. During this staking process, the 

subcontractor submitted any proposed changes to the design plans to the District Traffic Engineer, 

who verified the revisions and made recommendations to SCDOT Headquarters for final approval, 

as shown in Figure 5. The contractor then held a kick-off meeting with the relevant District Office to 

review the construction plans for intersections within the work order. 

Due to the importance of keeping the intersection improvements uniform across the State, a high 

level of communication between stakeholders was necessary during construction. The contractor 

and the subcontractor, SCDOT Headquarters, and the District Offices regularly communicated 

throughout the implementation of the project and kept each other up to date on activities in the 

field. The subcontractor had a field project representative who traveled between construction 

sites in a given area to provide oversight. SCDOT District Inspectors were also in the field during 

installation. District Inspectors either approved work if it was completed per the plan drawings or 

created a punch list if there were deviations from the plan. The inspectors confirmed the quantity 

and type of work performed for payment to the contractor. 

If during the installation phase it was discovered that an adjustment to the plan was required— 

for example, if it was found that the proposed location for a new sign post conflicted with 

underground utilities—the subcontractor would submit recommendations to the District Traffic 

Engineer. The District Traffic Engineer reviewed and verified recommended changes and 

Photo Credit: Joey Riddle, South Carolina Department of Transportation 

Example of signing adjustments to be made after field inspection. 

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South Carolina Case Study: Systematic Intersection Improvements
 

submitted them for approval to SCDOT 

Headquarters. The contractor and the 

subcontractor developed a field installation 

workbook that contained all pertinent 

information on construction at a particular site, 

including final approved drawings, installation 

checklists (Figure 6), and punch list forms. A 

process flow chart for the project was defined 

and is shown in the appendix. 

In addition, to maintain a record of inventory 

over the course of the fast-paced project, 

the contractor and subcontractor developed 

a reconciliation spreadsheet (Figure 7) to 

manage multiple crews and to document and 

verify installed quantities for payment. SCDOT 

developed a project overview spreadsheet to 

track the completion status of various phases 

of each work order, as shown in the appendix. 

Figure 5. Approved Construction Drawing 

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Figure 6. Sign Installation Checklist 

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South Carolina Case Study: Systematic Intersection Improvements
 

Figure 7. Reconciliation Spreadsheet 

Use of Project Management Web site 

The bid documents outlined requirements for a project management internet site that the 

contractor developed and maintained for the duration of the project. This project management 

website was a deviation from standard practices due to the project’s large size and complex 

logistics, as compared to contracts typically awarded by SCDOT. The website was primarily used 

to provide data to SCDOT on a regular basis and to report the progress of work performed on the 

contract. Contract documents defined the minimum requirements of the website; however, the 

website developed ultimately included more features. 

Table 1 illustrates the Web site data requirements for pavement markings and traffic signs, as 

specified in the bid documents. Additional requirements can be found in the SCDOT’s Proposal, 

“Contract and Bond for Highway Construction ‘Intersection Improvements’ for project #: SA09(002).” 

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Table 1. SCDOT’s Data Requirements for Internet Website 

Pavement Markings Traffic Signs 

Road name/Highway # (intersections) 

Work Order # 

Quantities of material installed 

Type of material used 

Field Supervisor name 

Status of work – planned or completed 

Start Date 

Finish Date 

Date Evaluated 

Evaluation results – durability and retroreflectivity 

(PDF file download option) 

Road name/Highway # (intersections) 

Work Order # 

GPS coordinates of each traffic sign location 

Sign ID # (bar code of new signs) 

Sign ID # (bar code – removed signs/posts) 

Ex. Signs had ID # and posts have an Assembly # 

MUTCD code for each sign type 

Sign dimensions (width and height) 

Sign face substrate 

Post type/style 

Date of sign installation 

Sheeting type 

Sign face direction 

Field Supervisor name 

Status of work – planned or completed 

Approval date – utility locates 

Start Date of Work Order 

Finish Date of Work Order 

Results of Implementation 

Realization of Safety Benefits 

To date, safety analyses have not been conducted on this 3-year project. An FHWA study will 

evaluate the safety effects of SCDOT’s low-cost systematic intersection improvements—one of 

several evaluations that will be conducted as part of the FHWA Evaluation of Low Cost Safety 

Improvements Pooled Fund Study (ELCSI PFS). 

Public Reaction/Input 

Following the improvements in the first year of the contract, overall public reaction was positive. 

Some feedback indicated dissatisfaction with certain visual and aesthetic impacts of the 

improvements, such as larger, brighter signage in close proximity to private property or in historic 

districts. However, such comments became less frequent over time, especially as citizens began 

to understand the safety benefits expected from the installation of the treatments. 

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South Carolina Case Study: Systematic Intersection Improvements
 

Lessons Learned 

Ability to Adjust the Contract 

All stakeholders on the project emphasized that mutual flexibility was an important key to the 

success of this project. Contract documents cannot account for the myriad of possible variables 

when dealing with hundreds of individual intersections. It was essential to “expect the unexpected” 

and be prepared to communicate in a timely and informative manner in order to deal with the 

inevitable issues that arose (e.g., proposed sign placement conflicted with utilities equipment). 

Communication 

The unique nature and logistics of a project of this sort, with hundreds of sites spread around an 

entire state, make communication vital. The contractor and subcontractor, SCDOT Headquarters, 

and the District offices communicated regularly during the planning and construction phases 

of each work order. SCDOT District personnel performed site inspections during the installation 

stage, and both District Inspectors and the in-field contracting team signed off on any required 

alterations to the plans before routing them to SCDOT Headquarters for approval. Communication 

between the subcontractor and SCDOT Headquarters became less frequent after the initial 

months of the project as they developed a relationship of mutual trust and understanding. 

Communication to the public was also an important aspect of this project, as it is on any 

construction project with impacts visible at the community level. Future projects would benefit 

from more outreach in historic districts to address the concerns of the residents without sacrificing 

potential safety improvement treatments. In addition, it may be beneficial to use social media 

outlets to communicate when and where construction is taking place. 

Contract Type 

For future projects, SCDOT would likely consider issuing a Request for Qualifications (RFQ) or 

Request for Proposals (RFP) to determine the technical qualifications of engineering services 

contractors before going through the low-bid process. Because of the complexity of the project 

and the design-build elements it entailed, SCDOT suggests using a hybrid approach that 

combines low-bid contracts awarded to pre-qualified contractors with pre-qualified engineering 

services subcontractors, rather than strictly using a low-bid process. Table 2 lists some of the 

advantages and disadvantages of the low-bid and qualifications-based contracts cited by the 

various stakeholders. 

Lesson Learned: Communicate early and often...and expect the unexpected. 15 
 

Table 2. Advantages/Disadvantages of Low-bid and Qualifications-based Contracts 

Low-bid Qualifications-based 

Advantages Disadvantages Advantages Disadvantages 

Fast decisionmaking 

process 

Bidders may not 

have technical 

qualifications 

Technical proposals 

provide opportunity 

for contractors 

to demonstrate 

technical capabilities 

Longer 

decisionmaking 

process 

Lowest upfront cost 

to State 

Additional costs if 

winning contractor is 

not capable 

Work is more 

efficient/reliable and 

State has confidence 

in work being 

conducted 

Potentially higher 

cost due to technical 

qualifications 

The contractor and subcontractor recommended that other States use a qualifications-based 

approach that focuses on technical capabilities for future projects similar in nature to the 

systematic approach used in South Carolina. All noted that SCDOT was fortunate to find a very 

reliable and trustworthy contractor/subcontractor team for this project, but contracts that are 

strictly low-bid do not necessarily provide an opportunity for the State to understand the technical 

capabilities of the bidding firms. 

Additionally, SCDOT, the contractor, and the subcontractor all suggested that serious thought should 

be given to determining whether the firm conducting installations should be on the same contract 

as the firm conducting engineering services, as it provides the potential for a conflict of interest. 

Plans Development 

Initially, SCDOT provided site-specific drawings for the improvements to be made at each 

intersection during the first year. Due to the overwhelming quantity of plans to be produced, 

SCDOT opted to shift this work to four consulting firms, independent from the contractor, for the 

second and third years. 

Over the course of the project, the contractor and subcontractor developed a very strong 

understanding of SCDOT’s expectations for the proper application of the signing and marking 

treatments and had considerable involvement in the revisions of the drawings provided by the 

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South Carolina Case Study: Systematic Intersection Improvements
 

consultants. However, both the contractor and the subcontractor noted that it would have been 

easier to either draw the plans themselves or have a single consulting firm draw all the plans to 

avoid discrepancies between the drawings. 

The subcontractor and contractor stated that the drawings, like those provided by SCDOT and 

their consultants, needed to provide enough detail to be considered a construction drawing. 

Changes had to be made to the original site-specific drawings based on realities in the field, and 

revisions were often necessary. 

Inspection Responsibility 

Rather than dividing inspection responsibilities by District and having many staff members 

throughout the State, the subcontractor suggested that SCDOT have the same set of inspectors 

working on sites throughout the State. This would reduce the need for re-education of District staff 

and would ensure a more consistent inspection process statewide. 

Future Steps 

For the second and third years of the systematic intersection improvements, SCDOT used 

consultants to produce site-specific drawings for the remaining intersections identified in the 

ISIP. SCDOT has also indicated they are considering separating the installation work from the 

engineering services portion of the contract and using a process to determine the technical 

capabilities of engineering services subcontractors through an RFP/RFQ process before initiating 

the low-bid process. 

SCDOT is planning to conduct a large, statewide curve improvement project using a systematic 

approach similar to that used in the intersection improvement project. 

References 

1. Intersection Safety Implementation Plan Process, FHWA-SA-10-010. 

http://safety.fhwa.dot.gov/intersection/resources/intersaf_ipp0709/fhwasa10010.pdf 

2. A Focused Approach to Safety Guidebook, FHWA-SA-11-44. 

http://safety.fhwa.dot.gov/fas/guidebook.cfm#intersectionhighlights 

3. Low-Cost Safety Enhancements for Stop-Controlled and Signalized Intersections, FHWA-SA-09-020. 

http://safety.fhwa.dot.gov/intersection/resources/fhwasa09020/fhwasa09020.pdf 

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Total: 2021

Appendix 

Project Overview: Stage Completion 

South Carolina Low Cost Intersection Improvements Project 3/22/2012Contract ID: 47.038390

Work 

Order # 

SCDOT

District # 

No. of

Intersections 

Original 

Drawings 

Received 

Field

Staking 

District Plan 

Review 

SCDOT HQ

Review 

Sign

Fabrication 

Sign

Installation 

Long Line 

PM Install 

Hand Work 

PM Install 

Sign Punchlist 

Work 

PM

Punchlist 

Work 

PM

Reflectivity

Readings 

29 1 41 Yes Complete Complete Complete Complete Complete 

Underway

03/20/12 

Underway

03/19/12

(8 Int. left) 

30 1 45 Yes Complete Complete Complete Complete Complete 

Underway

03/20/12 

Planned 

(start 03/26/12) 

33 5 75 Yes Complete Complete Complete Complete 

Underway

03/14/12 

Underway

03/20/12 

34 5 26 Yes Complete Complete Complete 

Underway

03/15/12 

Planned

(start 04/09/12) 

Planned 

(start 04/18/12) 

31 1 42 Yes Complete 

Underway

03/12/12 

24 2 44 Yes 

Underway

03/15/12 

32 2 43 Yes 

Projected

(start 03/29/12) 

35 1 41 Yes 

36 1 42 Yes 

37 1 41 Yes 

38 1 45 Yes 

39 3 45 Pending 

40 3 44 Pending 

41 3 47 Pending 

42 3 43 Pending 

43 6 59 Yes 

44 6 47 Yes 

45 6 59 Yes 

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South Carolina Case Study: Systematic Intersection Improvements
 

Process Map Flow Chart 

A Technical Document to Aid The South Carolina Department Of Transportation (SCDOT), 

the Contractor, and the Subcontractor During Document Chain of Custody. 

Order Entity Description 

Step 1 SCDOT HQ Post Work Order 

Step 2 Contractor Publish Work Order To Project Website 

Step 2A Subcontractor Conduct Field Engineering Review & Stake Sign Locations 

Step 3 Contractor Prepare Intersection ID Document Labels 

Step 3A Subcontractor Prepare Work Order Plan And Staking Review Document 

Step 4 Subcontractor Schedule District Work Order Planning Meeting – 

Communicate Review Requirements And Approval Process 

Step 5 SCDOT District Review & Edit Work Order Plan And Staking 

Document 

Step 6 SCDOT 

HQ Review & Approve Or Deny Culmination Of Field 

Engineering And District Edits Post Approved Final Work 

Definition Document 

Step 7 Contractor Build Sign Detail Sheet And Order Traffic Signs 

Step 8 Subcontractor Correct Sign Staking (As Necessary) 

Step 9 Contractor Prepare Detailed Work List For Installation Crews 

Step 10 Contractor Produce And Distribute Field Workbooks 

Step 11 Contractor Publish Approved Work Order Diagrams To Project Web Site 

Step 12 Contractor Publish Work Schedule To All Parties And On Project Web 

Site 

Step 13 Contractor Mobilize Installation Contractors 

Step 14 SCDOT HQ Review And Approve Fields Corrections. (Real Time) 

Step 14A SCDOT District Identify Potential Field Corrections 

Step 14B Subcontractor Identify Potential Field Corrections 

Step 15 SCDOT District Inspect Work As It Occurs 

Step 15A Subcontractor Inspect Work As It Occurs 

Step 16 Contractor Maintain Punch List And Publish To Project Web Site 

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For More Information: 

Visit http://safety.fhwa.dot.gov 

South Carolina 

Department of Transportation 

855-GO-SCDOT (855-467-2368) 

South Carolina Division 

Federal Highway Administration 

830-765-5411 

FHWA-SA-12-021 

Revised June 2020