Case: Guillermo vs Napa County

Expert Analysis and Testimony for Solo-Vehicle Rollover Collision

Location: Butts Canyon Road South of Snell Valley Road
Napa County, CA

Client: Johnston & Hutchinson LLP
Thomas J. Johnston, Esq.
Los Angeles, CA

Case Description

Solo-Vehicle Rollover Collision

Incident Overview:

This case involved a solo-vehicle rollover collision that occurred on Butts Canyon Road in Napa County under daylight conditions. A northbound vehicle was descending a 9%+ grade and negotiating a 400-foot radius curve when the right-side wheels left the paved shoulder, encountering an edge drop-off. The driver reacted by sharply turning the wheel to remount the pavement but lost control of the vehicle, causing it to overturn. The rollover resulted in serious injuries to the occupants, and the vehicle had a minor collision with a second vehicle during the rollover.

Services Provided:

Highway Maintenance Procedures Analysis: EES reviewed Napa County’s maintenance procedures, focusing on how edge drop-offs were managed and if regular maintenance could have prevented the hazardous condition.

Curve Warning Sign Evaluation: Our team analyzed the placement and adequacy of warning signs along the curve where the accident occurred, assessing whether they met regulatory standards and adequately warned drivers.

Highway Design Review: EES conducted an in-depth evaluation of the highway design, including the grade, curve radius, and overall layout of the roadway, to determine if design flaws contributed to the rollover.

Accident History Review: We researched the accident history along this section of Butts Canyon Road, investigating whether similar incidents had occurred due to roadway conditions.

Roadway Edge Drop-Off Analysis: EES examined the severity of the edge drop-off and its impact on the driver’s loss of control. Our analysis included the adequacy of shoulder conditions and the risk posed by the edge drop-off.

Roadside Clear Recovery Zone Assessment: Our team assessed the presence and adequacy of a roadside clear recovery zone, which is designed to give drivers a safe area to recover in the event they leave the roadway.

Issues Addressed

Highway Maintenance Procedures

Evaluating the County’s Maintenance Practices EES reviewed the maintenance procedures followed by Napa County to determine if proper protocols were in place to address and prevent hazardous conditions, such as edge drop-offs. Our investigation focused on whether regular maintenance inspections were conducted and if appropriate measures were taken to maintain safe roadway conditions.

Curve Warning Signs

Assessing the Placement and Effectiveness of Warning Signs The placement and effectiveness of curve warning signs are critical in preventing accidents on sharp curves. EES evaluated whether the curve warning signs were adequately positioned, clearly visible, and properly maintained to inform drivers of the upcoming curve, helping to prevent similar accidents.

Highway Design

Analyzing the Roadway’s Grade and Curve Design The design of the roadway, particularly the steep grade and sharp curve, played a significant role in this case. EES conducted a detailed review of the highway’s design to assess whether the grade and curve radius were appropriate for the location, considering the potential hazards they posed to drivers.

Accident History

Investigating Prior Incidents on the Roadway EES researched the accident history of the specific section of Butts Canyon Road to determine if similar accidents had occurred due to hazardous road conditions. A pattern of incidents could indicate that the roadway design or maintenance was insufficient.

Roadway Edge Drop-Offs

Examining the Impact of the Edge Drop-Off on the Accident The edge drop-off was a crucial factor in the driver’s loss of control. EES examined the depth and condition of the drop-off, evaluating whether it exceeded acceptable safety limits and contributed to the accident. Our analysis also included the condition of the shoulder and whether it provided adequate space for recovery.

Roadside Clear Recovery Zone

Assessing the Safety of the Roadside Environment EES assessed the adequacy of the clear recovery zone along the roadway. The presence of a safe recovery area could have mitigated the severity of the accident. Our analysis focused on whether a sufficient recovery zone was in place and how it may have impacted the driver’s ability to regain control.

Client Benefits

Thorough Analysis of Road Conditions: Our detailed analysis of highway maintenance, design, and roadside conditions provided crucial insights into the cause of the accident and the role played by Napa County’s infrastructure.

Informed Legal Strategy: EES’s findings allowed the legal team to build a strong case based on the inadequacies in the roadway’s design, maintenance procedures, and safety measures.

Credible Expert Testimony: Our expert testimony helped clarify complex technical issues, including roadway design and maintenance protocols, providing the court with a clear understanding of the contributing factors in the case.