Not all shipping containers are created equal. At PortMiami, you'll see dry boxes stacked next to refrigerated units, flat racks loaded with project cargo, and open-tops for oversized goods. Each type requires different drayage equipment, costs more or less to haul, and has specific handling rules. Let's break down what matters for your bottom line.
Dry Containers (Dry Boxes) are your bread-and-butter: steel boxes, weatherproof, standard 20ft or 40ft. Most import/export cargo rides in these. Basic, reliable, cheapest to haul.
Reefer Containers (Refrigerated) have active cooling systems. They need power—either a genset (generator) at the warehouse or a reefer plug at the port terminal. Carry perishables: fruit, fish, pharmaceuticals, frozen goods. Heavier payload, specialized handling.
Flat Rack Containers are open platforms with fold-down sides. No roof. Built for oversized or project cargo: machinery, steel coils, breakbulk goods. Require tarping (covers) and often permit handling on public roads (overwidth/overheight).
| Dimension | Dry Container | Reefer Container | Flat Rack |
|---|---|---|---|
| Typical Cargo | General merchandise, apparel, electronics | Fruit, fish, meat, pharmaceuticals | Machinery, coils, project cargo |
| Tare Weight (Empty) | 2,200 lbs (20ft) / 3,850 lbs (40ft) | 3,200 lbs (20ft) / 5,900 lbs (40ft) | 2,600 lbs (20ft) / 4,850 lbs (40ft) |
| Max Payload | 47,800 lbs (20ft) / 52,150 lbs (40ft) | 46,800 lbs (20ft) / 49,100 lbs (40ft) | 45,400 lbs (20ft) / 47,150 lbs (40ft) |
| Power Requirement | None | Yes (genset or plug at port/warehouse) | None (but tarping needed) |
| Drayage Cost (Typical Miami) | $600–$800 | $850–$1,200 | $750–$1,100 |
| Special Equipment | Standard chassis | Reefer chassis + power source | Flat rack or open-top chassis + tarp |
Reefers aren't just heavier—they're complex. The refrigeration unit consumes fuel or electric power. At PortMiami, reefer plugs at the terminal are premium real estate. Wait times are longer because the chassis has to stay powered.
Real scenario: You pick up a reefer at PortMiami bound for a warehouse in Hialeah (15 miles). The reefer unit is running the whole way—fuel burn is real. At the warehouse, if they don't have a reefer plug, you're paying for a genset rental ($200–$400/day). The cargo can't sit without cooling, so you can't drop-and-hook. You wait while they unload.
Flat racks look cheap—they're just platforms. But project cargo brings complications.
Weight distribution matters. A coil of steel can look small but weigh 35,000 lbs. If it's not centered, your axles are overweight. Florida DOT will stop you and fine you. Overweight permits cost $25–$50 per trip.
Overwidth/overheight cargo (anything wider than 8'6" or taller than 13'6") needs oversize permits. Those run $100–$300 depending on route. You may need police escorts in some jurisdictions.
Tarping is non-negotiable for anything exposed. If it rains and the shipper's cargo gets damaged, they sue you for the difference. A quality tarp costs $200–$500 and keeps moisture and UV off the load. Most drayage operators charge $75–$150 to tarp and cover.
Here's something people miss: lighter containers (dry boxes) mean less axle weight. You have more payload capacity. But heavy containers (reefers, loaded flat racks) fill your truck faster, especially by weight.
In Miami's port congestion, if you're sitting at the dock with a light load (you're only using 30,000 of your 80,000-lb capacity), detention eats your profit fast. Heavy containers mean you're maxed out faster, which means you can command higher rates.
1. Ask about equipment. Do they have standard, reefer, and flat-rack chassis? Specialists who focus on one type are often cheaper for that type but can't handle mixed cargo.
2. Understand their reefer strategy. Do they own gensets? Do they partner with warehouses that have reefer plugs? Are they familiar with the reefer chain for perishables (inspections, certifications)?
3. Check tarping experience. For flat racks and oversize, you want a company that's done it. Bad tarping = claims = money out of your pocket.
4. Confirm permit handling. Oversize moves need expertise. Are they tracking overweight/overheight regulations per route?
Dry containers are the cheapest and fastest. No special equipment, no power, no permits. If you're an importer moving general cargo, this is your lane.
Reefers cost 30–50% more because the cargo is perishable and the equipment is specialized. If you're shipping fruit or fish, the premium is non-negotiable. Your supplier or buyer eats it.
Flat racks require knowledge. Permits, tarping, weight distribution—one mistake costs thousands. Use a drayage company with flat-rack experience.
Know your container type before you book. Tell your drayage company exactly what you're hauling and they can quote accurately. Hidden surcharges for equipment or permits kill relationships fast.