Illinois Department of Transportation 

SUMMARY of Road Safety Audit REPORT 

Interstate 55 Work Zone: From US 6 to Weber Road 

Project Data 

Date: July 30-31, 2007

RSA Team and Participants: 

Dave Piper – Illinois Department of Transportation (IDOT) Bureau of Safety 

Engineering (BSE) 

Dennis Whitehead – IDOT BSE 

Brian Copple – Illinois State Police (ISP) 

Heidi Liske – Federal Highway Administration (FHWA) 

Background: 

The RSA was conducted on Interstate 55, between portions of US 6 and Weber 

Road. The focus of the RSA was to identify opportunities for safety 

improvements during construction activities and in work zone areas. Throughout 

the study, the RSA Team examined several risk factors that impact traffic safety 

on Interstate 55, including exposure, probability, and consequence. The RSA 

was conducted over a two-day period with a team that was comprised of law 

enforcement, transportation, and other local officials. 

Because of the changeable nature of a work zone, the RSA decision 

making process was accelerated to include discussion and acceptance of 

certain items at the close out meeting. 

RSA Process: 

The RSA was performed by conducting field studies along construction sites and 

work zones on Interstate 55. Specifically, the areas of study were located on 

Interstate 55, between US 6 and Weber Road. In addition, the RSA Team also 

examined crash history reports and statistics from several areas along the 

Interstate. This data was reviewed and synthesized by the RSA Team to help 

identify safety issues or concerns. The data was also used to identify roadway 

countermeasures that will help improve traffic safety. 

RSA Stage: Existing Road (reconstruction projects) 

Major RSA Findings 

Issue: Speed

Location: Work Zones on Interstate 55, between portions of US 6 and Weber 

Road 

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Illinois Department of Transportation 

Description of Safety Issue: 

One of the biggest safety issues along this portion of the Interstate is vehicle 

speed. In many instances, drivers travel through the work zones in excess of the 

legal speed limit. This is a major safety concern for both drivers and individuals 

who may be working along this portion of the Interstate or work zone. As a 

result, the RSA Team rated this issue as a high risk rating. 

Suggestion: The RSA Team recommended that the quality and number of speed 

signs be improved. It was also recommended that there be a greater State 

Police presence along this portion of the Interstate and a photo enforcement van 

should be utilized. As a long term recommendation, the RSA Team believes a 

speed management policy should be established and enforced. 

Issue: Speed Signage

Location: Work Zones on Interstate 55, between portions of US 6 and Weber 

Road 

Description of Safety Issue: 

The RSA Team noted that there are an insufficient number of speed signs along 

this portion of the Interstate. In addition, there is a lack of speed limit notification 

between some of the lane shifts. The RSA Team also noted that some of the 

existing speed limit signs lack consistent font type and retroreflectivity levels 

throughout the work zones. The RSA Team scored this issue as a moderate 

risk. 

Suggestion: 

The RSA Team recommended that additional speed signage be added 

throughout the work zones, including stretches of highway where lane shifts 

occur. It was also recommended that the overlay panels on the speed limit signs 

be updated so the font and retroreflectivity are consistent and easy to read. 

Issue: Shoulder Hazards 

Location: Work Zones on Interstate 55, between portions of US 6 and Weber 

Road 

Description of Safety Issue: There are several areas along this portion of the 

Interstate that have excess debris or hazardous objects on the side of the 

roadway. This debris or roadway material often gets blown or knocked onto the 

Interstate, impacting a driver’s ability to operate their vehicle safely. The RSA 

Team scored this issue as a moderate risk. 

Suggestion: The RSA Team recommended that scheduled garbage patrols be 

implemented to help remove debris along the Interstate. 

Issue: Vegetation Blocking Signs 

Location: Work Zones on Interstate 55, between portions of US 6 and Weber 

Road 

Description of Safety Issue: There are several areas along this portion of the 

Interstate where overgrown vegetation has obstructed the views of traffic 

signage, including speed limit, work zone, and lane shift signs. As a result, this 

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Illinois Department of Transportation 

may prevent drivers from viewing or complying with Interstate traffic signs while 

driving. The RSA Team scored this issue as a moderate risk. 

Suggestion: The RSA Team recommended that obstructive vegetation be trimmed 

or removed to increase traffic signage visibility. 

Issue: Low Guardrail 

Location: Work Zones on Interstate 55, between portions of US 6 and Weber 

Road 

Description of Safety Issue: There are several areas along this portion of the 

Interstate that have low guardrails. During a traffic incident, the existing 

guardrails may not adequately prevent vehicles from leaving the roadway. As a 

result, this may increase the severity of traffic accidents. The RSA Team scored 

this issue as a moderate risk. 

Suggestion: The RSA Team recommended adding guardrail delineation. In 

addition, the RSA Team also suggested that crashworthy guardrails be tested 

and implemented during design stages. 

Issue: Stage I - Narrow Lanes 

Location: Work Zones on Interstate 55, between portions of US 6 and Weber 

Road 

Description of Safety Issue: There are several areas along this portion of the 

Interstate that have narrow lanes. The RSA Team scored this issue as a 

moderate risk. 

Suggestion: Ensure effective and accurate striping for this portion of the 

Interstate. 

Issue: Narrow Shoulders 

Location: Work Zones on Interstate 55, between portions of US 6 and Weber 

Road 

Description of Safety Issue: There are several areas along this portion of the 

Interstate that have narrow shoulders. As a result, this may restrict drivers from 

pulling off the roadway after a traffic accident or during vehicular malfunctions. 

The inability to use the shoulder during these types of situations may cause lane 

blockages or excessive traffic delays. It may also increase the level of roadway 

exposure for individuals. The RSA Team scored this issue as a moderate risk. 

Suggestion: The RSA Team recommended guardrail delineation. It was also 

recommended that effective and accurate stripping be maintained along this 

portion of the Interstate. 

Issue: Coordinated Work Zone Signage 

Location: Work Zones on Interstate 55, between portions of US 6 and Weber 

Road 

Description of Safety Issue: There are several closely adjacent work zones along 

this stretch of highway that do not have coordinated signage. As a result, it may 

be difficult for drivers to know when they are entering or leaving work zone areas. 

The RSA Team scored this issue as a moderate risk. 

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Illinois Department of Transportation 

Suggestion: As a long term recommendation, the RSA Team recommended the 

development of a policy and/or standards to address this issue 

Other RSA Findings 

The RSA also produced several other findings. These include conflicting 

pavement markings, lack of “trucks use left lane” signage, sign clutter, adverse 

super elevation, lack of dual display signage on southbound approaches, and 

confusing type 3 barricade signals. These findings, however, received low – 

minimal risk ratings from the RSA Team. 

 

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