Quick Answer
A fleet tracking system is a GPS device in each truck or trailer plus software that shows where every unit is. The device gets its position from GPS satellites and sends it over a cellular network to a web dashboard or app. Truck units also read engine data (speed, miles, engine hours, faults) from the ECM. Dispatchers use the data for ETAs, theft recovery, detention records, and IFTA miles.
Key Takeaways
- GPS gives the position; a cellular modem sends it to the cloud. Without cell coverage, most devices store pings and upload them later.
- Hardwired and plug-in units draw truck power and read engine data. Battery trailer trackers report less often to save battery.
- FMCSA does not require real-time tracking under the ELD rule, but carriers may track trucks in real time for business purposes.
- An ELD must record location at each duty status change and at least once an hour while the truck is moving, accurate to about 1 mile.
- During personal conveyance, ELD location drops to about a 10-mile radius under 49 CFR 395.26.
- Carriers may monitor productivity with ELD data but may not use it to harass a driver into an hours-of-service or fatigue violation (49 CFR 390.36).
“A fleet tracking system uses a GPS receiver in each truck or trailer to find its position and a cellular modem to send that position to a web dashboard. Engine data comes from the truck's ECM. ELDs record location by rule, but FMCSA does not require real-time tracking.”
How does a GPS fleet tracking system work?
Every fleet tracking system works the same basic way, whether you run one truck or fifty.
- A GPS receiver in the device calculates latitude and longitude from satellite signals.
- The device reads vehicle data. Hardwired and plug-in units connect to the truck's diagnostic port and pull speed, odometer, engine hours, fuel use, and fault codes from the engine control module (ECM).
- A built-in cellular modem sends each reading (a "ping") to the provider's servers.
- The software plots pings on a map, builds a breadcrumb trail, and fires alerts based on rules you set.
- You see it all on a web dashboard or a phone app.
The ping interval is set by the device and the plan. Shorter intervals give a smoother trail and faster alerts. Longer intervals save battery and data, which matters most on trailer trackers.
If the truck drives through a dead zone, most devices keep recording and upload the stored pings when the signal returns. The GPS position itself does not need cell service. Only the upload does.
What is a fleet tracking device?
A fleet tracking device is the hardware that captures location and sends it to your software. There are three common types.
Device type | Power source | Engine data | Typical use |
|---|---|---|---|
Hardwired tracker | Truck electrical system, installed behind the dash | Yes, if wired to the data bus | Permanent install, harder for a thief to find and pull |
Plug-in tracker or ELD | Truck's diagnostic port | Yes | Quick install, moves between trucks, often combined with the ELD |
Asset or trailer tracker | Internal battery, sometimes solar | No | Trailers, containers, and equipment without power |
Most small fleets start with a plug-in unit because the ELD they already need can do double duty. Trailer trackers are a separate purchase, since a trailer has no engine port to plug into.
What does a vehicle monitoring system track?
A vehicle monitoring system shows more than a dot on a map. Here is what fleets typically see in the dashboard:
- Location and history: live position, breadcrumb trail, stop times, and arrival and departure at each stop.
- Speed and motion: current speed, speeding events, and idle time.
- Engine data: odometer, engine hours, fuel use, and diagnostic fault codes from the ECM.
- Hours of service: if the tracker is part of an ELD, each driver's remaining drive time and duty status.
- Driver behavior: harsh braking, hard acceleration, and, with AI dash cams, events like tailgating or phone use.
- Geofence events: alerts when a truck or trailer enters or leaves a shipper, receiver, yard, or truck stop.
The ELD side has its own fixed data list. Under 49 CFR 395.26, an ELD automatically records date, time, CMV location, engine hours, vehicle miles, driver ID, vehicle ID, and motor carrier ID at each duty status change. If you are new to the device itself, start with what an ELD is and what it records.
What do fleets use GPS truck tracking for?
The best uses save time on the phone and turn disputes into records.
- Dispatch and ETAs: You see where the truck is instead of calling the driver. Many brokers also ask for load tracking through visibility apps such as MacroPoint.
- Proximity search: When a broker offers a load, a proximity search shows which of your trucks is closest to the pickup. That helps when you are finding loads for a small fleet.
- Detention documentation: Geofence arrival and departure times at a shipper give you a timestamped record of how long the truck sat. That record backs up a detention claim better than memory does.
- Theft recovery: A live position on a stolen tractor or trailer gives police something to act on.
- IFTA miles: GPS and odometer data split miles by state automatically, which cuts the paperwork behind quarterly IFTA reporting.
Lucid ELD's Standard plan includes real-time GPS tracking, proximity search, and integrations with Highway and MacroPoint alongside the ELD.
How do trucking companies prevent trailer theft and unauthorized drops?
Cargo theft is a real cost, not a scare story. Verisk CargoNet recorded 3,594 supply chain crime events in the U.S. and Canada in 2025, with estimated losses near $725 million, up 60% from 2024. In its Q2 2026 report, incidents fell to 677, but estimated losses more than doubled to $304.6 million. CargoNet also recorded fewer organized thefts of unattended, loaded trailers that quarter, while email-compromise and shipment-misdirection schemes held steady.
Tracking helps in a few specific ways:
- Trailer trackers: A battery unit on each trailer shows where it is even when no tractor is hooked to it.
- Geofences: Draw a zone around your yard, the shipper, and approved drop lots. You get an alert when a trailer leaves a zone or appears somewhere it should not be.
- Drop alerts: Compare the trailer's position with the tractor's. If the tractor moves on and the trailer stays behind at an unplanned spot, dispatch sees it right away.
- After-hours movement alerts: A trailer moving at 2 a.m. on a weekend is worth a phone call.
- Plain security habits: King pin locks, glad-hand locks, and parking loaded trailers in secured, lit lots still matter. A tracker helps you recover a trailer. A lock helps keep it from leaving in the first place.
Tracking does not stop fraud done by email or fake carrier identities. That takes carrier vetting and broker verification, which is a separate problem from GPS.
ELD vs GPS tracker: is an ELD a GPS tracker?
An ELD records location, but the rule does not make it a live GPS tracker. Its legal job is to log hours of service. Location is one data point attached to each logged event.
Under the ELD technical specifications (49 CFR part 395, subpart B, appendix A):
- Position must be accurate to plus or minus 0.5 mile and recorded to two decimal places, which works out to about plus or minus 1 mile.
- The ELD must get a valid position at least once every 5 miles of driving, but it records location only at required events.
- While the truck is moving, it adds an intermediate record if there has been no other record in the past hour (395.26(d)).
- The display and printout show location as distance and direction from a nearby city, town, or village, not a street address.
So the ELD log alone gives roughly hourly, roughly 1-mile points. A live map with frequent pings comes from tracking software that runs on the same hardware or a separate device. FMCSA's guidance says real-time tracking is not required by the ELD rule, but a carrier may use it for business purposes.
What are the privacy and legal rules for tracking drivers?
Federal rules put a few clear limits on how ELD location data is recorded and used.
Personal conveyance gets reduced precision. When a driver indicates authorized personal use, the ELD records location to one decimal place, about a 10-mile radius, and leaves engine hours and vehicle miles blank on intermediate records (395.26(d)(2) and (i)). See the personal conveyance rules for when PC applies.
No harassment. Under 49 CFR 390.36, a carrier may not use ELD information to push a driver into violating the fatigue rule in 392.3 or the hours-of-service rules in part 395. The same section says carriers can still use allowed technology to monitor productivity, as long as that does not become harassment. A driver can file a written complaint with FMCSA under 386.12(b).
No coercion or data alteration. 49 CFR 395.30 bars a carrier from coercing a false certification and from altering or erasing original HOS data.
No jamming or tampering. 49 CFR 395.8(e) bars drivers and carriers from disabling, jamming, or blocking an ELD's signal so it does not record required data. A GPS jammer that kills the ELD's position is a violation, not a privacy fix.
Federal ELD rules do not cover every tracking question. Tracking a personal phone or a separate GPS unit can fall under state privacy or employee-monitoring laws. Put your tracking policy in writing, tell drivers what is tracked and when, and check your state's rules before you install anything beyond the ELD.
Educational content, not legal advice. Confirm requirements against current FMCSA regulations and your state's rules.
FAQ
What is a fleet tracking system?
A fleet tracking system is GPS hardware in trucks or trailers plus software that shows each unit's location, speed, and engine data. Devices send position over cellular networks to a dashboard where dispatchers see the fleet on a map.
Does the ELD rule require real-time GPS tracking?
No. FMCSA guidance says real-time tracking of CMVs is not required by the ELD rule. A motor carrier may still track trucks in real time for business purposes.
How accurate is ELD location data?
During normal operation, ELD location is accurate to about plus or minus 1 mile under the appendix A specifications. During authorized personal conveyance, it drops to about a 10-mile radius.
Can a GPS tracker work without cell service?
The GPS receiver finds its position from satellites without cell service. Most devices store those pings and upload them once the truck is back in coverage.
Can my carrier track me during off-duty time?
The ELD keeps recording during personal conveyance, but at reduced location precision of about 10 miles. Other tracking devices and policies vary by carrier and state law, so ask for the written tracking policy.
Do trailers need a separate tracker?
Yes, if you want to see a trailer when it is unhooked. An ELD or truck tracker follows the tractor, so trailers need their own battery-powered asset tracker.
