Over the last year, a prototyping and experimentation team at the Massachusetts Department of Transportation called The Lab @ MassDOT has been digging into truck safety, focusing on direct vision and vehicle retrofits as part of the implementation of state law. 

The study, which examined 60 vehicles, found that downsizing generally improves visibility, with heavy-duty vehicles having the worst visibility. 

Chief Possibility Officer at MassDOT, Kris Carter, who helps run The Lab @ MassDOT, broke down recommendations on fleet visibility, downsizing, and retrofitting with safety devices. 

Reducing Traffic Fatalities in Massachusetts 

To understand the research from the Lab @ MassDOT it’s important to go back a few years when An Act to reduce traffic fatalities went into effect in 2023. Part of this included a requirement for side guards, crossover mirrors, convex mirrors, and backup cameras on all state-owned or leased vehicles. 

Fleets operating a unit over 10,000 pounds will need those four devices installed on them beginning next year. 

The second part of this was looking at direct vision. This led to a survey in which MassDOT worked with the U.S. DOT Volpe Center to examine 60 different vehicles, including Class 3 vehicles and light-duty vehicles, such as Ford F-150s and F-250s, Silverados, and 2500s. 

“We developed a methodology with Volpe on how to measure direct vision and spent a few months trying to come up with that process so it could be standardized across all the vehicles,” Carter explained. “Then we went out and measured part of the Massachusetts fleet, which was about 20 vehicles.” 

The team partnered with 10 cities and towns to measure their fleets, focusing on vehicles that weren’t already in the U.S. DOT fleet and were Model Years 2015 and newer. This resulted in the 60 vehicles chosen. 

The study looked at the distance to where a reference-height person — about 5’ 7” — walking or biking first became visible in the forward and passenger directions to a driver with a standardized eye position. The analysis revealed that there was a significant variation of direct vision performance across light, medium, and heavy-duty vehicles. 

What initially stood out to the team was that, overall, downsizing was the better option for a fleet, as this simply meant better visibility. 

“The light-duty vehicles have the highest visibility in the fleet, medium-duty the next, heavy-duty the worst,” Carter noted. 

However, while the first part of this finding was relatively straightforward what was shocking was the degree of visibility, or lack thereof. About 50% of the drivers using heavy-duty vehicles in the study couldn't see a child directly in front of the unit in a crosswalk, while 90% of them couldn't see a child in the bike lane. Looking out the passenger side, about 80% couldn’t see an adult in the bike lane.

The third piece to this puzzle was finding that driver visibility wasn’t just bad; it had been getting worse. This finding came about while looking at Class 3 and Class 4 vehicles and finding that visibility was decreasing with newer generations of legacy models. 

“The trend is largely going the opposite direction we would like it to go,” Carter said. The study stacked vehicles against each other to determine visibility into a crosswalk or a bike lane. 

Another test measured the visibility to the ground for the driver to be able to see the ground. When these results were overlaid on top of each other to be compared, looking at different years, models, and makes, that was when the decrease in visibility became evident.

Recommendation for Fleets Based on Test Findings

For fleets looking to make improvements in regard to safety, the first recommendation is to measure the fleet. This recommendation is based on methodology developed by the City of Boston and Together for Safer Roads. 

While the MassDOT study used a measuring system that required specialized tools and software, a good approximation can be done by using two traffic cones to measure how far forward and to the passenger side a median-height male driver can see a given vulnerable road user (VRU) from the vehicle. With the seat in mid-height, mid-track position a person in the driver seat instructs another person to move the cone until visible. Two measurements would be taken: 

The distance forward of the center of the vehicle bumper at which the person can first see the top of a three-foot cone is the forward distance to a child VRU. 

The distance beyond the exterior of the passenger side door at which the person can first see the top of the four-foot cone. This is the passenger side distance to an adult VRU. 

A second recommendation is to prioritize adding cabover or cab forward designs versus conventional designs when buying new vehicles, as the study found that these particular designs have significantly better front visibility. 

Another option would be to include language government contracts that favor vehicles with better visibility. For example, in the Massachusetts’ VEH11 state contract — regarding heavy-duty vehicles, road maintenance, and construction equipment — language could be used to prompt departments to purchase high-vision vehicles whenever possible. 

Additionally, the team reported that fleets could combine electrification with direct vision as trucks without an engine block can have improved direction vision compared to conventional cab diesel trucks. 

A final recommendation is retrofitting the fleet. This can mean adding additions such as crossover mirrors, 360-degree cameras, blind spot warning detectors, and side guards. Carter explained that fleets need to know their blind spots and then try to mitigate those challenges for the drivers. 

However, retrofitting also means spending additional money, which isn’t always easy for fleet owners. Carter said that because of this, the next piece on their agenda is to figure out how to make funds more accessible for public fleets and where those funds would come from. 

Taking a Proactive Approach to Vehicles 

Speaking with fleet managers and drivers the team found that there was a general awareness if a particular vehicle didn’t have the best visibility. This had fleets taking different approaches, from drivers deciding to not even take out vehicles where they had poor visibility to others being able to tackle the issues with retrofitting. Some fleets had even found alternative routes that were better in terms of visibility. However, in the end, the team found that the drivers who had some high-vision cabs reported to have much less stress during their driving tasks. 

“Our hope for fleet managers is that in addition to fuel economy and the function of the vehicle, they're really thinking about its visibility as well and using that as part of how they're thinking through the decision to buy a new vehicle,” said Carter. “I think that helps push the market.”

Key Takeaways 

1. Downsize the vehicle whenever possible. On average, light-duty vehicles had the highest visibility in fleets studied. 

2. Drivers in heavy-duty vehicles cannot easily see people on the street. Drivers in 90% of the trucks studied could not see a child in the bike lane and 80% could not see an adult in a bike lane. 

3. Driver visibility is mostly getting worse. Visibility in weight class 3 and 4 vehicles appeared to be decreasing in newer generations of legacy models.