How do you dispatch dump trucks and concrete without the chaos?
Updated · Reviewed by Israel Margulies, founder and CEO of High Point GPS
Dump truck dispatch works when you send enough trucks to keep the loader or the pour busy, and no more. You get that number from the round-trip cycle time divided by how often the site can take a load. Concrete adds a clock: each load has a time limit from batching to discharge, so spacing the trucks matters as much as counting them.
Trucks needed
Round-trip cycle time ÷ Time between loads the site can take
Hypothetical: a loader fills a truck every 6 minutes and the full cycle (load, haul, dump, return) takes 42 minutes. 42 ÷ 6 = 7 trucks.
What dump truck dispatch balances
Every haul has a loading end and a dumping end, and both cost money while they wait. A loader with an operator sitting idle because the next truck is stuck at a light is lost production. Five trucks queued behind the loader with engines running are lost production too, plus fuel. Your job as dispatcher is to keep that line short at both ends.
Break the cycle into its parts and time them on a real day: loading, hauling loaded, dumping or spreading, returning empty, and the wait at each end. The wait is the part you control. Haul distance and loader speed come from the job.
How many trucks a job needs
Divide the full cycle time by the time it takes to load one truck, or for concrete, by the interval between loads the pour can accept. The answer is rarely a whole number, and the rounding is a business decision. Round down and the loader waits for trucks. Round up and trucks wait at the loader. Compare what an hour of each costs you and round toward the cheaper idle.
Recheck the count when the job changes. A second dump site farther out, a new detour or an afternoon rush hour lengthens the cycle, and the truck count that worked at 7 a.m. falls short by 2 p.m.
- Time five or six real cycles before you trust an estimate
- Count the scale and the ticket window as part of the cycle
- Keep one spare truck on call for long days, so a breakdown doesn’t stall the loader
- Move trucks between jobs when one site’s cycle shortens
Concrete dispatch: spacing trucks against the clock
Each ready-mix load comes with a deadline. The Caltrans construction manual tells inspectors to make sure truck-mixer discharge finishes within 1 1/2 hours or 250 drum revolutions after the cement meets the aggregates, and to set a shorter time when the concrete is 85°F or above. Wisconsin DOT’s standard spec allows 60 or 90 minutes for agitating trucks depending on concrete temperature and whether an approved retarder is used. Your project spec sets the number that applies; read it before you plan.
That clock changes how you dispatch. Send loads at the rate the crew can place them, not as fast as the plant can batch. Every truck queued at the pump is a load using up its discharge time. Plan from the pour rate backward. In a hypothetical pour, the crew places a load every 15 minutes and each truck’s full cycle is 75 minutes: loading at the plant, the drive out, 15 minutes discharging at the pour, washout and the drive back. Divide 75 by 15 and you need five trucks on that pour, leaving the plant 15 minutes apart. If your 75 minutes covers only the driving, add the plant and discharge time before you divide, or you will send too few trucks.
Legal loads and the weight question
Overloading a dump truck is easy because the loader operator fills by eye. On the Interstate System, 23 CFR 658.17 sets a maximum of 80,000 pounds gross, 20,000 pounds on a single axle and 34,000 pounds on a tandem, with lower limits where the bridge formula requires. States set their own limits on other roads and issue permits for non-divisible loads, so a full load of aggregate on a local road may face different numbers than the same truck on the Interstate.
Make the scale ticket part of the routine. Tell loader operators the target weight for each truck type, and review overweight tickets weekly with the operator who loaded them. Overloads also add wear to brakes, tires and suspensions, and you pay for that in the shop.
Start-of-shift checks and site safety
On an off-highway construction site, OSHA 29 CFR 1926.601 requires a check of each vehicle at the start of every shift: service and parking brakes, emergency stopping system, tires, horn, steering, coupling devices, seat belts, operating controls and safety devices. Defects must be corrected before the vehicle goes into service. Dispatch depends on this check, because a truck that fails it at 6:45 is a truck you don’t have at 7.
The same standard covers dump-specific items: a reverse signal alarm audible above site noise or an observer for backing, a cab shield when a loader or shovel fills the truck, a dump body support locked in place for maintenance, and tailgate trip handles placed so the operator is clear when dumping.
What construction dispatch software should cover
Software for hauling and concrete splits into two jobs. One is the haul itself: tickets, loads, tonnage per truck, job and phase codes, and for ready-mix, the link to the batch plant. The other is the fleet behind it: which trucks are running, which are due for service, and how equipment gets moved between sites.
Products tend to specialize in one of them, so decide which gap hurts more. If you lose money on uncounted loads, start with ticketing and tonnage. If trucks keep failing pre-trip checks or a loader sits on the wrong site for a day, start with maintenance and equipment moves.
Where FleetZap fits for dump truck and mixer fleets
FleetZap does not count loads, print haul tickets or connect to batch plants. It handles the fleet and the equipment moves. Dump trucks and mixers get preventive maintenance by engine hours, miles or date, and drivers do their start-of-shift check by scanning the QR label and filling in a checklist on their phone. A failed item opens a repair work order, and the driver can take the truck out of service from the same phone, so the office sees it before assigning the truck.
The dispatch module plans the moves that put machines on site: a lowboy taking the loader or paver to a new job, a broken machine coming back to the shop. Each move gets a Google Maps arrival estimate and a check of the machine’s shipping weight against the truck’s payload, and Optimize orders a driver’s run around time windows. You can see it with sample data in the live demo.
Key takeaways
- When the loader's idle hour costs more than a truck's, round the truck count up; on a job with a cheap loader and expensive trucks, round down.
- Retime the cycle whenever the dump site, the route or the time of day changes by enough to add a few minutes each way.
- On a hot-weather pour, ask the inspector for the shortened discharge time before the first truck leaves, and space trucks to that number.
- Hold one truck back from the morning plan until the start-of-shift checks are in, so a failed check doesn't cost you a load.
Sources
FleetZap Dispatch
Deliveries, pickups, routing and a driver app. Explore FleetZap Dispatch.
Frequently asked questions
How do you calculate how many dump trucks you need?
Time the full cycle for one truck: loading, hauling loaded, dumping, returning empty and waiting. Divide that by the time it takes to load one truck. A hypothetical 42-minute cycle with a 6-minute load needs 7 trucks. If the result is a fraction, round toward whichever is cheaper for you: the loader waiting or the trucks waiting.
What does a dump truck dispatcher do?
A dump truck dispatcher assigns trucks to jobs, keeps loaders and pavers supplied without long queues, moves trucks between sites as cycle times change, and handles breakdowns, weather and customer changes. On ticketed work they also track loads and tonnage. Good dispatchers time real cycles on site instead of trusting the estimate from the bid.
What is concrete dispatch software?
Concrete dispatch software schedules ready-mix orders, assigns trucks to pours, spaces loads to match the placing rate and tracks each ticket from batching to discharge. Many products link to the batch plant controls. When you compare tools, check how each one handles the discharge time limit in your project specification and a pour that slows down.
How long can concrete stay in the truck?
It depends on the project specification. The Caltrans construction manual uses 1 1/2 hours or 250 drum revolutions after the cement meets the aggregates, with a shorter time when the concrete is 85°F or hotter. Wisconsin DOT allows 60 or 90 minutes for agitating trucks depending on temperature and retarder. Always use the limit in your own contract.
What is the best dump truck software?
Pick by your biggest loss. If loads and tonnage go uncounted, choose a ticketing and haul-tracking product. If trucks fail inspections, miss service or machines end up on the wrong site, choose maintenance and dispatch software for the fleet. Some fleets run one of each and link them through exports.