The summer of 2024 brought record-breaking heat, pushing both vehicles and drivers to their limits. Road surface temperatures spiked, vehicle breakdowns increased, and driver fatigue became more frequent, creating a more hazardous driving environment. As we head into another potentially extreme season, the risks for fleet drivers remain high, from engine strain and tire blowouts to unpredictable traffic patterns. Whether your fleet includes gas-powered vehicles, hybrids, or EVs, these tips will help keep drivers safe and operations running smoothly during the dog days of summer.

Tire Safety: The First Line of Defense 

Tire blowouts are more common in extreme heat, as hot pavement and underinflated tires create a dangerous combination. Proper tire maintenance is crucial for every fleet vehicle. Drivers should be trained to inspect tires before each shift, checking for tread depth, punctures, and proper inflation levels as listed in the vehicle manual or door frame. 

In fact, according to the National Highway Traffic Safety Administration (NHTSA), underinflated tires are up to three times more likely to be involved in a crash. If your fleet is equipped with tire pressure monitoring systems (TPMS), ensure they are functioning properly and drivers are trained to respond to alerts immediately. 

Batteries and Cooling Systems: Keep Engines and Drivers Cool 

Heat is hard on batteries. Excessive temperatures can accelerate fluid evaporation, shortening battery life, especially in older fleet vehicles. For internal combustion engines (ICE), regular testing of batteries and maintenance of cooling systems should be scheduled before peak summer. 

Fleet EVs face a different challenge: heat management. High ambient temperatures reduce range and increase stress on the battery. Many EV manufacturers recommend limiting fast charging in high heat and parking in shaded areas to help reduce battery degradation. If your EV has thermal battery management, confirm it's functioning properly. 

Electric Vehicles: Heat Aware Driving Strategies 

As more fleets incorporate electric vehicles, operators must consider how heat impacts performance. While EVs may have fewer moving parts and require less maintenance, battery systems are sensitive to extreme temperatures. 

Fleet drivers should: 

• Precondition the cabin while the vehicle is still plugged in, preserving driving range. 

• Avoid charging during peak heat hours when possible. 

• Monitor EV telematics to detect signs of battery overheating. 

In high heat, EV range can drop by up to 20%, especially when A/C use is high. Route planning and regular charging intervals should be adjusted accordingly. 

Visibility and Glare: Small Steps, Big Impact 

Summer glare is more than just an inconvenience; it’s a safety hazard. Bright sunlight can obscure traffic signals, pedestrians, and other road users. A dirty windshield amplifies the glare effect by scattering light. Ensure that your drivers are:

• Equipped with quality, polarized sunglasses. 

• Regularly cleaning windshields inside and out. 

• Checking washer fluid levels and wiper blade condition weekly. 

A clean line of sight is one of the most overlooked components of defensive driving.

Construction and Congestion: Plan to Avoid Delays 

Summer is peak roadwork season. Detours, reduced speed limits, and sudden traffic pattern changes can frustrate drivers and increase the risk of crashes. Encourage fleet drivers to:

• Use real-time GPS apps to plan routes and avoid construction zones. 

• Obey all signage and give road crews extra room. 

• Leave early when traveling through high-volume tourist areas or during peak hours. 

Fleet managers can integrate construction alerts into dispatch tools or driver dashboards for greater awareness and efficiency.

Increased Pedestrian and Tourist Activity: Expect the Unexpected 

With schools out and vacationers on the move, drivers should anticipate more pedestrians, often distracted or unfamiliar with local traffic patterns. This is especially true near parks, stadiums, beaches, and campgrounds. Drivers should: 

• Reduce speeds in high-foot-traffic areas. 

• Watch sudden stops, erratic driving, or jaywalking. 

• Be ready to brake if a child darts into the road unexpectedly. 

A cautious, alert driver is the fleet’s best defense in these unpredictable environments.

Fatigue and Impairment: Silent Summer Risks 

Long daylight hours and busy social calendars increase the risk of driver fatigue and impaired driving in the summer. These remain two of the top contributors to fleet collisions each year. To mitigate risk: 

• Emphasize mandatory rest breaks every 2 hours or 100 miles. 

• Encourage 7–8 hours of sleep prior to shifts. 

• Reinforce zero-tolerance policies for alcohol and drug use, particularly following summer events or holidays. 

Fleet policies should also address cannabis use (especially in legal states), prescription medication impairments, and provide education on recognizing signs of fatigue.

Technology: A Summer Safety Ally 

Modern fleets are increasingly equipped with advanced driver assistance systems (ADAS) that can help mitigate heat-related risks. Features like forward collision warning, automatic emergency braking, and driver attention monitoring can make a measurable difference. Fleet managers should: 

• Ensure ADAS features are activated and calibrated. 

• Offer training on how to properly use these systems without overreliance. 

• Use telematics to track driver behavior, vehicle diagnostics, and identify early warning signs of fatigue or mechanical failure.

Emergency Preparedness: Expect the Unexpected 

Every vehicle in your fleet should be equipped with a summer-ready emergency kit, including: 

• Water bottles 

• First-aid supplies 

• Reflective vests 

• Road flares or triangles 

• Portable phone chargers 

• Heat-reflective windshield shades

 During the July 2024 Operation Safe Driver Week, law enforcement issued over 4,000 citations and warnings to commercial vehicle operators nationwide. The top violation? Speeding, responsible for 1,694 warnings and 1,226 citations. Other common infractions included failure to wear seat belts and the use of handheld devices while driving, each one a preventable action with potentially life-altering consequences. As we reflect on those numbers, it’s clear that safety doesn’t begin and end with the driver alone. It’s a shared responsibility, one that stretches across every layer of an organization.

 Summer doesn’t just challenge vehicles; it challenges drivers. By taking a proactive approach to fleet safety and adapting protocols for warmer weather, you not only reduce liability and operational downtime but also show your drivers you care about their well-being. 

Your fleet is only as strong as the people behind the wheel. Let’s keep them safe, cool, and prepared for every mile of summer.

Editor’s note: This article was originally published in August 2023 and has been updated for continued relevance.