A new study indicates there are “potential benefits” to allowing truck drivers more flexibility when taking required hours-of-service breaks, according to the American Transportation Research Institute.

ATRI said on Aug. 28 that, using empirical truck GPS data to model the application of split rest beyond the 8- and 2-hour increments allowed under the existing HOS rules, its analysis found that drivers could spend less time and money while driving the same distances.

Under current HOS rules, drivers are required to rest for at least 10 hours before starting a new 14-hour work day.  With one exception, the 10 hours must be consecutive.  As a result, drivers who take a break to avoid congestion may lose available work hours, ATRI noted.

However, ATRI pointed out, there are “innovative HOS concepts that, if implemented, would enable drivers to avoid congestion by taking strategic periods of rest; a rest period of 3 or more hours that qualifies toward the daily 10-hour rest requirement could effectively help drivers avoid slow-moving peak travel periods.”

The study made use of a representative “freight-significant” 40-mile stretch of urban highway in Atlanta to quantify the operational impacts of congestion.  The initial assessment using the truck GPS data showed that the time it took to traverse the congested corridor ranged from a low of 40 minutes to over 90 minutes during rush hours— which amounts to a more than doubling of driving time and related operational costs.

Operational truck GPS data was used to identify a sample of 3,600 truck trips that traversed the study corridor.  Average speeds and travel times by hour of day were calculated for each trip – which quantified significant congested periods that lasted well beyond 2 hours.  Lost time and operational costs were calculated for each hour of the day; the peak period calculations were found to be more than double the time and cost of off-peak travel.  

“Not surprisingly,” states ATRI, “the results indicate that AM and PM peak travel times (when commuters have the greatest demand for urban interstate highways) had the lowest average speeds and highest average travel times across the 40-mile study area.” Travel times indicate a fastest travel time of 39.9 minutes to traverse the corridor from 1:00 to 1:59 am and a slowest travel time of 1 hour and 33.4 minutes to traverse the corridor when trips start between 4:00 and 4:59 pm.  “Thus, there is a range of 53.5 minutes between the best and worst travel times, indicating that the 40-mile trip could take nearly one hour longer to complete depending on the time of day travel commences.”  

ATRI said it then modeled scenarios in which a “representative driver” operated under the current HOS rules and a “flexible” 6/4 split rest time.  Under the flexible hours, the driver was able to avoid congestion, and completed a 585 mile trip with 45 fewer minutes of drive time.  Similar results were also found for 7/3 and 5/5 split scenarios.

Per ATRI, the analysis modeled two scenarios with a driver traveling across a heavily congested 40-mile urban corridor as part of a 585-mile trip using current and flexible HOS options. Using the flexible option, traversing the 40 miles required 45.5 minutes less driving time “because a 4-hour rest break allowed the driver to avoid a relatively small (40-mile) segment of urban interstate during peak travel times.”

If only 25 truck trips per day avoided the congested weekday time period presented on the study segment, ATRI added, “truck drivers would drive 4,700 fewer hours annually to move the same goods the same distance. This equates to operational cost savings of more than $300,000 per year for the 25-truck sample at that single location.”

Were the study results replicated across the industry, according to ATRI, “a conservative estimated savings in annual drive time of more than 2.3 million hours could be realized with flexible HOS options,” along with over $150 million in annual operational cost savings.

ATRI said the analysis provides “an assessment of how flexible HOS rules could be applied to enable a single representative driver the ability to avoid congestion in a single study area.” The group noted there hundreds, if not thousands, of “severe chokepoints” in the nation where these rules could be applied by HOS-regulated drivers.

“The time savings, cost savings, and decreased drive time that could result from implementation of a 7/3, 6/4 or 5/5 split sleeper berth rule, while unknown, are likely quite large,” said ATRI.

"One of our biggest challenges with the HOS rules is the lack of flexibility,” commented said Gary Helms, an over-the-road driver for Covenant Transport and an America's Road Team Captain. “Under the current rules, when traveling through congested cities, I really have no choice but to sit stuck in traffic and watch my available hours tick away.  As ATRI's study shows, with flexibility in the HOS, I could choose to rest during the worst congested times and make my delivery schedules with less time behind the wheel."

The research group said the study was undertaken, in part, in response to ongoing discussions by industry stakeholders, including the Federal Motor Carrier Safety Administration, on how flexibility in sleep and rest time could benefit drivers.

A copy of the full report is available online from ATRI.