ELDs and driver fatigue: what electronic logs show, what they miss and how to plan real rest
What electronic logs record, where they fall short and how to schedule for real rest
Safety Behind the Wheel Foundation built this guide from Federal Motor Carrier Safety Administration (FMCSA) rules and guidance, Insurance Institute for Highway Safety (IIHS) data, the hours of service rules of Texas, California and New York, and published research on driver fatigue. Every source is listed at the end.
Why duty tracking matters on shared roads
Large trucks share the road with families every day. In 2024, 5,340 people died in large truck crashes, and 62% of them were in cars or other passenger vehicles [10]. Researchers have found that fatigue and drowsiness are a major cause of truck collisions, and that lack of sleep is the top cause of fatigue [11].
Fleets use two tools to manage this risk. An electronic log answers one question: how long did the driver work? A fatigue aware scheduling tool tries to answer another: did the plan leave a real chance to rest? Neither one tells you whether a driver is alert right now.
This guide is for owners and managers of delivery, service, trucking and rideshare operations, and for anyone who hires them. Our guide to work driving fatigue covers shift rules and trip decisions. This article looks at the tools.
What an ELD records, and what it leaves out
A driver’s daily log of work and rest periods is called a record of duty status [2]. An ELD creates that record automatically. It connects to the vehicle, so it does not depend on a driver writing times by hand.
By rule, an ELD records the date, time, vehicle location, engine hours, vehicle miles and the identity of the driver, plus vehicle and carrier details [1]. While the vehicle moves, it adds a record if an hour passes with no other entry [1]. During authorized personal use, location is logged only to about a 10 mile radius [1].
Nothing on that list measures sleep, alertness or how a driver feels. The device knows when the truck moved, not whether the driver slept five hours or nine. A log records time, and fatigue is a state of the body.
Who must use one under federal law
A motor carrier is a company that moves people or goods for business. Under the federal rule, a carrier that operates commercial motor vehicles must install an ELD and require each driver to use it. The deadline was December 18, 2017 [2].
Three groups may keep manual logs instead. One is drivers who need a log on no more than 8 days in any 30 day period. Another is certain driveaway towaway drivers, where the vehicle being driven is the shipment. The third is drivers of vehicles built before model year 2000 [2].
The rule covers only commercial motor vehicles. The federal definition refers to interstate commerce, which means trade or travel across state lines. A vehicle counts if its weight rating is 10,001 pounds or more [3]. It also counts if it is designed or used to carry more than 8 people, including the driver, for pay [3]. A typical rideshare car is built for far fewer people than that, so it usually falls below the passenger line [3]. Some cargo vans also have a weight rating below the line, while larger box trucks may not. Find the gross vehicle weight rating on the manufacturer’s label, often on the driver’s door frame. Then ask a compliance professional how the rule applies to you.
Operators outside the federal definition can still track duty time as a safety practice. The American Academy of Sleep Medicine has called fatigue and sleepiness inherent safety risks in ridesharing. It noted that many drivers fit driving around another job, which can mean driving after long waking hours or at night [12]. It also said that company rest period rules are encouraging but not enough alone. It called for effective fatigue risk management systems [12]. Safety Behind the Wheel Foundation supports that approach for every fleet. That term means policies, scheduling rules, training and reviews that work together to limit tired driving.
How state rules differ
The federal definition refers to interstate commerce [3]. Vehicles that stay inside one state may fall under that state’s rules instead. As of October 2026, some states borrow the federal text and others write their own limits. Three examples show the range.
Comparison compiled by Safety Behind the Wheel Foundation
How three states handle hours rules for in state trips
| State | What the rule text says | What to notice |
|---|---|---|
| Texas | Adopts federal safety rules, including parts 390 to 393 and 395 to 397, as amended through September 1, 2022. Treats an in state vehicle as commercial above 26,000 pounds, with a higher line for farm vehicles [7] | The federal text is frozen at a date. The weight line is higher than the federal 10,001 pounds [3] |
| California | Truck drivers may not drive more than 12 hours after 10 hours off, or after the 16th hour on duty. Carriers keep time records [8] | Limits differ from the federal 11 hour and 14 hour limits [13] |
| New York | Adopts federal Part 395 for in state trips, with exceptions for some farm work, tow trucks on roadside calls and utility service vehicles [9] | Exceptions depend on the job, not just vehicle size |
These pages show different dates. California’s section was last amended in December 2019 [8], and New York’s took effect in July 2015 [9]. A carrier that runs in one state should ask that state’s agency how ELDs apply to its trips.
What the research says about ELDs
The best evidence comes from fleets. One study used data from 11 medium and large carriers, covering 82,943 collisions and 224,034 truck years of driving [5]. After the researchers accounted for other factors, trucks with ELDs had an 11.7% lower total crash rate and a 5.1% lower preventable crash rate than trucks without them [5]. Their rate of driving related hours violations was 53% lower [5].
ELDs have been promoted as safety tools partly because falsifying an electronic log is difficult [5]. They make hours rules harder to bend.
Two cautions apply. The study was observational, so it compared trucks as they operated and did not assign devices at random. Its data also leaned toward larger for hire carriers and may not represent all trucking [5]. It looked at collisions and hours violations, not at whether drivers were rested.
Why a legal log can still hide a tired driver
Federal rules treat fatigue as its own problem. A driver may not operate a commercial vehicle when fatigue makes it unsafe to begin or continue, and a carrier may not require or permit it [4]. The only exception is a grave emergency where stopping would add to the hazard [4]. So a log inside every limit does not settle the question.
Time off duty is not the same as sleep. A field study followed 96 truck drivers across 1,397 shifts [11]. The sleep pattern with the highest rate of safety critical events involved shorter sleep, sleep early in the off duty period and less sleep between 1 a.m. and 5 a.m. [11]. Those events included collisions, near crashes, crash relevant conflicts and unintended lane drift [11]. Two drivers with identical logs could have very different nights.
The hours limits are blunt tools. They allow up to 11 hours of driving inside a 14 hour window after 10 hours off duty [13]. A driver can finish a legal 10 hour break and still start the next shift tired. Logs also miss what happens off the clock, such as a second job or a noisy place to sleep.
What fatigue aware scheduling tools add
Fatigue aware scheduling software looks beyond hours worked. Many tools use a biomathematical model, a computer formula that estimates alertness from work and rest history and the time of day. A scheduler can test a draft roster and see which shifts look risky before anyone drives them.
Such tools work best as support for hours limits, not a substitute. One review of rail industry research concluded that validated models may be used inside a fatigue management system to add protection beyond limits on work and rest hours [6]. The same review linked shifts longer than 12 hours to a doubling of accident and injury risk. It also found that fatigue builds when rest between shifts is under 12 hours [6]. That review looked at rail, not trucking, so ask any supplier for evidence from work like yours.
Scheduling also depends on where drivers can stop. A statewide crash study by University of Kentucky researchers compared at fault commercial driver collisions that cited sleepiness or fatigue with those that cited other human factors [14]. The odds of a fatigue related collision were about 2.3 times higher when the nearest rest area or truck stop was 20 to 39.9 miles away, compared with under 20 miles [14]. They were about 6.8 times higher at 40 miles or more, and such collisions were also more likely at night [14]. Plan breaks near safe places to stop, not only at set clock times.
Good questions for any supplier include:
- Has the model been checked against real alertness data for work like your fleet’s?
- Does it use sleep history, or only hours worked?
- Can you see how it reached a risk score?
- Does it treat night work differently from day work?
Using log data fairly
Logs hold sensitive facts about where drivers are and how they work, so federal rules limit how carriers may use them.
A carrier may not harass a driver. The rule defines harassment as using ELD information to push a driver toward breaking the hours rules or the fatigue rule. It applies when the carrier knew, or should have known, that this would be the result [15]. Pressure to keep driving because a route is unfinished is the kind of pressure it targets.
Drivers keep some control over their records. Each edit needs an explanation, and an edit proposed by anyone other than the driver must be confirmed or rejected by the driver. Drivers must be able to see their own records, and carriers must protect driver privacy in a way consistent with sound business practices [1]. No driver or carrier may make a false report about duty status [2].
Set written rules on who can see location and log data and how long you keep it. Carriers must keep logs and supporting documents for at least 6 months [2]. For coaching ideas, see our guide to fleet telematics and driver cameras.
Choosing, installing and maintaining a system
Fleet technology suppliers sell ELDs. A typical package includes installing hardware in each vehicle and a recurring software service that stores logs and builds reports. Get more than one quote.
Start with legal fit. A carrier must use a device on the FMCSA’s registered ELD list [1]. Then check practical fit. Carriers may set up ELDs so drivers can mark authorized personal use and yard moves, such as moving a truck around a private lot [1]. Ask whether the system handles those settings and can share data with your scheduling tools.
Plan for failures. If an ELD malfunctions, the driver must rebuild the log for the current 24 hour period and the previous 7 days on paper [1]. Keep blank paper logs in each vehicle and practice the steps. Review unassigned driving each week. These are driving records with no driver logged in, and carriers must keep them for at least 6 months [1].
A weekly routine for reading logs with fatigue in mind
- Pull the past week’s logs and next week’s planned schedule.
- Mark any shift that starts right after the minimum off duty time or runs close to the daily limits [13].
- Mark drivers whose start times swing between day and night in the same week.
- Find the longest stretches between safe stopping places on each route.
- Check edits and unassigned driving, because bad data hides real patterns.
- Talk with drivers about sleep and workload, then change the schedule where needed.
- Write down what changed, and check the same signals next week.
Comparison compiled by Safety Behind the Wheel Foundation
Log patterns that may signal fatigue
| Log pattern | What it may signal | Question to ask |
|---|---|---|
| Start times swing between day and night | Lost sleep in the 1 a.m. to 5 a.m. window [11] | Can starts shift later in small steps? |
| Next shift starts right after the minimum rest | Little time for commute, meals and sleep [13] | How much sleep fits in this gap? |
| Long runs between rest stops | Fewer places to rest [14] | Where can the driver stop safely? |
| Many edits or unassigned driving | Data gaps that hide patterns [1] | Who drove, and why was it missed? |
Common mistakes
- Treating a compliant log as proof of an alert driver.
- Editing logs without notes or the driver’s approval.
- Letting unassigned driving pile up.
- Skipping the paper backup plan.
- Using location data to push drivers rather than to plan rest.
- Trusting a fatigue score without asking how it was tested.
Frequently asked questions
Does an ELD tell me if a driver is too tired to drive?
No. The data an ELD must record covers time, place, engine hours, miles and identity, not sleep or alertness [1]. Federal rules separately bar driving when fatigue makes it unsafe [4]. Use logs to spot risky schedules, then talk with drivers about sleep.
Do delivery vans and rideshare cars need an ELD?
Not necessarily under the federal definition. It covers vehicles rated at 10,001 pounds or more and vehicles built or used to carry more than 8 passengers for pay [3]. Many cars and some vans fall below those lines. State rules may differ [7, 8], and employers can adopt their own duty tracking policies. Ask your state agency or a compliance professional about your vehicles.
Can a manager change a driver’s log?
Only in limited ways. Every change needs an annotation, and an edit requested by anyone other than the driver must be confirmed or rejected by the driver [1]. False reports about duty status are prohibited [2]. If a manager sees a mistake, a sound practice is to ask the driver to propose the fix.
What should a driver do if the ELD stops working?
Rebuild the log for the current 24 hour period and the previous 7 days on paper [1]. Carry blank paper logs, tell your manager, and ask the supplier for a repair timeline. Practice these steps before a failure, so nobody learns them at the roadside.
Can a fatigue scheduling tool replace driver reports?
No. A tool estimates risk from schedules and sleep history, but it cannot see illness, noise or sleep disorders. The American Academy of Sleep Medicine notes that obstructive sleep apnea, a breathing problem during sleep, can reduce alertness [12]. Combine model results with open fatigue reports, medical screening and the right to stop.
The bottom line
Recommendation from Safety Behind the Wheel Foundation
Safety Behind the Wheel Foundation urges fleets to treat logs as a starting point for fatigue safety, not proof of a rested driver. An ELD does its job well. It records work time accurately, makes hours rules harder to bend and gives managers useful data. It does not measure alertness. Treat it as the base layer of a fatigue plan, not the whole plan.
Pair logs with schedules that leave real time to sleep and safe places to stop. Use data fairly, and give drivers a clear right to say, “I am too tired to drive.” If you hire a carrier, ask how it tracks hours and rest. Ask suppliers for the evidence behind any fatigue claims.
Related articles
Sources and further reading
- 1U.S. Government Publishing Office and Office of the Federal Register (eCFR). 49 CFR Part 395, Subpart B: Electronic Logging Devices (sections 395.20 to 395.38). Updated: current through October 2, 2026. ecfr.gov/…/subpart-B
- 2U.S. Government Publishing Office and Office of the Federal Register (eCFR). 49 CFR 395.8: Driver’s record of duty status. Updated: current through October 2, 2026. ecfr.gov/…/section-395.8
- 3U.S. Government Publishing Office and Office of the Federal Register (eCFR). 49 CFR 390.5: Definitions (commercial motor vehicle). Updated: current through October 2, 2026. ecfr.gov/…/section-390.5
- 4U.S. Government Publishing Office and Office of the Federal Register (eCFR). 49 CFR 392.3: Ill or fatigued operator. Updated: current through October 1, 2026. ecfr.gov/…/section-392.3
- 5Hickman JS, Guo F, Camden MC, Dunn NJ, Hanowski RJ. Traffic Injury Prevention 18(3):312-317. An observational study of the safety benefits of electronic logging devices using carrier-collected data. Published June 20, 2016. doi.org/10.1080/15389588.2016.1201201
- 6Anderson C, Grunstein RR, Rajaratnam SMW. Internal Medicine Journal 43(6):717-721. Hours of work and rest in the rail industry. Published June 2013. doi.org/10.1111/imj.12159
- 7Texas Department of Public Safety rule, as reproduced by the Cornell Legal Information Institute. 37 Tex. Admin. Code section 4.11: General Applicability and Definitions. Amended effective January 8, 2023. law.cornell.edu/…/37-Tex-Admin-Code-SS-4-11
- 8California Highway Patrol regulation, as reproduced by the Cornell Legal Information Institute. Cal. Code Regs., tit. 13, section 1212: Driver Hours of Service. Last amended December 23, 2019; operative April 1, 2020. law.cornell.edu/…/13-CCR-1212
- 9New York State Department of Transportation regulation, as reproduced by the Cornell Legal Information Institute. N.Y. Comp. Codes R. & Regs., tit. 17, section 820.6: Hours of service of drivers. Effective July 1, 2015. law.cornell.edu/…/17-NYCRR-820.6
- 10Insurance Institute for Highway Safety. Fatality Facts 2024: Large trucks. Updated June 2026. Data year: 2024. iihs.org/…/large-trucks
- 11Chen GX, Fang Y, Guo F, Hanowski RJ. Accident Analysis and Prevention 91:55-63. The influence of daily sleep patterns of commercial truck drivers on driving performance. Published March 5, 2016. doi.org/10.1016/j.aap.2016.02.027
- 12Berneking M, et al. Journal of Clinical Sleep Medicine 14(4):683-685. The Risk of Fatigue and Sleepiness in the Ridesharing Industry: An American Academy of Sleep Medicine Position Statement. Published April 15, 2018. doi.org/10.5664/jcsm.7072
- 13Federal Motor Carrier Safety Administration. Summary of Hours of Service Regulations. Updated March 28, 2022. fmcsa.dot.gov/…/summary-hours-service-regulations
- 14Bunn TL, Slavova S, Rock PJ. Accident Analysis and Prevention 126:3-9. Association between commercial vehicle driver at-fault crashes involving sleepiness/fatigue and proximity to rest areas and truck stops. Published online November 22, 2017. doi.org/10.1016/j.aap.2017.11.022
- 15U.S. Government Publishing Office and Office of the Federal Register (eCFR). 49 CFR 390.36: Harassment of drivers prohibited. Updated: current through October 1, 2026. ecfr.gov/…/section-390.36
This article reflects the safety priorities of commercial driver fatigue prevention and fleet safety management. It is general education, not legal, medical or insurance advice. Rules change, so verify details with official sources. For your own situation, contact the Federal Motor Carrier Safety Administration, your state's motor carrier safety agency or a qualified compliance attorney. Drivers with sleep concerns should talk with a health care provider. Reviewed October 2026.
Cite this article: Safety Behind the Wheel Foundation. “ELDs and driver fatigue: what electronic logs show, what they miss and how to plan real rest.” drivewithcare.org, https://drivewithcare.org/electronic-logs-fatigue-aware-scheduling/. Reviewed October 2026.
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