Moving heavy haul freight between the United States and Mexico requires route engineering, advance permits in both countries, verified Mexico capable insurance, and a provider with proven heavy haul experience on both sides of the border. Plan 2–3 weeks ahead (or more) to secure specialized equipment and permits, choose the right crossing and transfer method, and share complete technical specs up front to avoid rework and delays.  

The following guidelines provide steps shippers can take to keep oversized freight moving safely, legally, and on schedule while crossing the border. 

1. Know When Your Freight Is “Oversize/Overweight” 

Oversize freight includes any load that exceeds the legal dimensions or weight limits defined by transportation authorities. Oversize freight thresholds differ by country and often by state/corridor and route.  

Common Oversize Freight Thresholds: U.S. vs. Mexico 

Governing Authorities 

Federal, state and local rules may govern transportation requirements.  It is important to know the weight and height for each load to comply with applicable regulations and prevent costly delays.

Key Takeaway: Verify the precise height and weight of each load and check oversize freight limits for each jurisdiction along the shipment route according to federal, state, and local regulations.   

2. Engineer the Route—And Select the Right Border Crossing 

Many heavy haul shipments require engineered routes designed to safely accommodate oversized freight. Work with a transportation provider experienced in cross-border and heavy haul operations to reduce the likelihood of unexpected detours and delays. 

Key Elements of Route Engineering  

• Structural Analysis 
• Geometric Assessment  
• Route Mapping and Modeling 
• Traffic & Safety Planning 
• Permitting and Compliance 
• Risk Mitigation  
• CrossBorder Route Considerations 

Border Infrastructure: Not all border gateways can accommodate heavy haul shipments. In Laredo for example, oversized or overweight freight is often routed through the Columbia bridge rather than the World Trade bridge, as it has wider lanes and higher clearances. Make sure the chosen gateway is compatible based   on the destination and restrictions identified during quoting.  

Customs Broker Authorized Ports: Shippers importing or exporting in Mexico are required to use a Mexico Customs Broker. Brokers can only file customs entries at a limited quantity of ports, which can unexpectedly limit heavy haul route options if not verified beforehand.  

Route Restrictions in Mexico: Mexico regulations require carriers to follow approved corridors to avoid narrow lanes, sharp curves, or bridge weight limits, especially in low-capacity rural roads. 

Key Takeaway: Heavy haul shipments demand precise route engineering and attention to border infrastructure and regulatory factors to prevent delays and mitigate risk. 

3. Secure Permits Early  

You’ll need separate oversize/overweight permits for every U.S. state and for each Mexican state along the route. Approvals, time of day windows, and escort rules vary. Begin applications 2–3 weeks before transit with complete cargo details (dimensions, weights, schematics/photos, hazmat info) to avoid rework or delay.

Permit Considerations by Country 

United States

• Issued by individual states
• Weight, dimension, route and time-window restrictions set at the state level  

Mexico 

• Federal permit  
• Often requires engineered route surveys, especially for multistate movements 
• Around holidays like Christmas and Holy Week, the Mexican government typically pauses permitting to keep heavy haul loads off the road during periods of increased non-commercial holiday traffic. 

Key Takeaway: Expect permitting to take 2–3 weeks before shipping and give your transportation provider detailed cargo information (photos, schematics, hazmat details) to avoid delays. 

4. Involve Your Customs Broker Early in the Planning Stage 

For heavy haul cross-border shipments, it’s wise to engage your customs broker in the planning phase as early as possible. They can help facilitate a smoother process by:  

• Reviewing cross-border paperwork for accuracy and compliance 
• Reducing chances of delays, fines, and shipment holds at customs 
• Coordinating with U.S. and Mexican authorities for efficient clearance 
• Advising proper classification of oversized freight 
• Providing guidance on requirements that change by port, state, or cargo type 

Key Takeaway: Engage your customs broker early to help prevent heavy haul shipment delays and compliance issues. 

5. Verify Freight Insurance Coverage for Mexico Transit 

Insurance requirements differ significantly between the U.S. and Mexico, making verification of proper coverage essential. 

Key Insurance Considerations 

• Mexican carriers are not legally required to carry cargo liability insurance 
• U.S. cargo insurance policies typically do not provide coverage that extends inside Mexico 
• Supplemental Mexico capable freight insurance is recommended, especially for high value, fragile or oversized loads 

Ask your provider about supplemental policies with Mexico coverage included, such as Landstar’s High Value Trip Transit (HVTT), which provides coverage in both the U.S. and Mexico. 

Key Takeaway: Mexican carriers aren’t legally required to carry cargo liability insurance, and U.S. policies typically don’t extend to Mexico. To protect your freight, verify cargo coverage on both sides of the border and ask your provider about supplemental policies. 

6. Choose Your Cross-Border Method: Transloading vs. Direct  

Trailer selection when crossing the border can impact cost, handling, and capacity availability.  

The two primary options are transloading and direct trailer.  

• Transloading (transfer of freight between trailers at a facility on the U.S. side of the border) provides broader carrier access but adds additional handling. You will need a carrier with access to heavy duty cranes and trailers that can accommodate your freight needs.
• Direct trailer (through-trailer) keeps freight on one trailer but limits carrier flexibility. It requires a transportation provider with established interchange agreements at the border and is also more likely to require deadhead for proper trailer positioning.

Select a provider that can offer both options to match handling requirements and route constraints. Landstar operates a facility in Laredo which  features an overhead bridge crane that can transload up to 120 tons. It also maintains over 270 interchange agreements with Mexican carriers to enable direct trailer moves. 

Key Takeaway: Freight can move across the U.S.–Mexico border by transloading or direct trailer methods. Having a carrier who offers both options provides flexibility based on individual shipment needs.

7. Work With an Experienced Cross-Border Heavy Haul Provider

Shipping heavy cargo across borders is easier when supported by an experienced transportation service who is familiar with managing regulations and procedures in each country.  

What to Look For 

Look for  CTPAT-validated operations, Mexico-compatible cargo coverage, bilingual teams, and the ability to support both transloading (with heavy lift capacity) and direct trailer via solid interchange networks. 

Landstar brings decades of cross-border heavy haul experience, a 120-ton bridge crane in Laredo, and 270+ interchange agreements to expand options and reduce delays. 

Key Takeaway: An experienced cross-border heavy haul provider can support seamless shipping by navigating regulations, maintaining safety standards, providing Mexico cargo insurance options, and offering both transloading and direct trailer solutions.