Guide to Kentucky Weigh Stations and Bypass Programs

Kentucky operates 14 permanent weigh station facilities and utilizes mobile enforcement units managed by the Kentucky State Police (KSP) Commercial Vehicle Enforcement (CVE) division. Unlike many other states, Kentucky requires a specific Kentucky Highway Use (KYU) number for any vehicle with a registered gross weight of 60,001 pounds or more. Compliance at these scales involves verifying weight limits, electronic logging device (ELD) data, and active tax accounts including IFTA and the KYU weight-distance tax. The state primarily enforces a federal bridge formula limit of 80,000 pounds on interstates, though specific state routes may have lower posted limits. DispatchTool helps carriers navigate these requirements by integrating truck-safe routing that accounts for Kentucky's specific restricted routes and bridge weights. The platform allows dispatchers to monitor driver proximity to scale houses and ensures all necessary KYU documentation is stored within the digital trip folder for easy access during an inspection. By automating the collection of miles traveled within Kentucky borders, DispatchTool simplifies the quarterly KYU-5 reporting process. Create a DispatchTool account to manage your Kentucky compliance documents and route around restricted parkways.

Permanent Scale Locations and Operations

Kentucky's primary weigh stations are located on major interstate corridors including I-65, I-75, I-64, and I-71. The Laurel County Northbound and Southbound scales on I-75 are among the busiest in the state, frequently conducting Level I North American Standard Inspections. Other significant sites include the Lyon County scales on I-24 and the Scott County scales on I-75. Most permanent facilities are equipped with Weigh-In-Motion (WIM) sensors located approximately one-half mile prior to the exit ramp. These sensors capture axle weights and gross vehicle weight at highway speeds. If the WIM system detects an overweight condition or an invalid credential, the electronic signage will direct the driver to pull into the facility for static weighing and document review.

Kentucky Highway Use (KYU) Number Requirements

The Kentucky Transportation Cabinet (KYTC) mandates the KYU number for all carriers operating vehicles at a gross weight of 60,001 pounds or higher. This is a permanent identification number used to track the Kentucky weight-distance tax, which is currently calculated at a rate of $0.0285 per mile. At weigh stations, KSP officers verify that the vehicle's USDOT number is associated with an active KYU account. Failure to have a valid KYU number or operating with a revoked account due to non-payment of taxes results in immediate citations and potentially a requirement to purchase a one-time temporary permit costing $40.00. The KYU-5 tax return must be filed quarterly, even if zero miles were traveled in the state during that period.

Bypass Programs: PrePass and Drivewyze

Kentucky participates in both the PrePass and Drivewyze electronic screening programs to reduce congestion at scale houses. To qualify for a bypass, a carrier must maintain a safety rating above the FMCSA's intervention threshold. When a truck equipped with a transponder or bypass app approaches a Kentucky scale, the system checks the carrier's ISS (Inspection Selection System) score and KYU tax status. If the data is current and the vehicle weight is within legal tolerances on the WIM sensors, the driver receives a green light to bypass. Statistics from the American Transportation Research Institute (ATRI) suggest that each weigh station bypass saves a carrier approximately $8.68 in fuel and operational costs and between 5 to 15 minutes of travel time.

Weight Limits and Federal Bridge Formula

On Kentucky interstates and designated state truck routes, the maximum gross vehicle weight is 80,000 pounds. Single axles are limited to 20,000 pounds, and tandem axles are limited to 34,000 pounds. Kentucky strictly adheres to the Federal Bridge Formula, which defines the relationship between the weight carried and the distance between axles (W = 500 [LN/(N-1) + 12N + 36]). For vehicles carrying divisible loads, such as coal or farm products, Kentucky Revised Statute 189.222 allows for specific weight increases on certain non-interstate highways, provided the carrier has obtained the necessary extended weight decals. Fines for overweight violations in Kentucky are graduated, often starting at $0.02 per excess pound and increasing significantly for loads more than 4,000 pounds over the limit.

KSP Commercial Vehicle Enforcement Inspections

Kentucky State Police (KSP) officers conduct inspections following the Commercial Vehicle Safety Alliance (CVSA) guidelines. A Level I inspection includes a thorough check of both the driver's credentials and the vehicle's mechanical components, such as brake systems, lighting, and coupling devices. Drivers must provide their ELD records for the previous 8 days. In 2023, the FMCSA reported that thousands of inspections in Kentucky resulted in out-of-service (OOS) orders for brake violations and hours-of-service non-compliance. Carriers with a high OOS rate are flagged in the system, resulting in a higher frequency of red lights at bypass-enabled weigh stations until their safety scores improve through clean inspections.

Permits and Overdimensional Regulations

Vehicles exceeding 8 feet 6 inches in width, 13 feet 6 inches in height, or 80,000 pounds in weight must obtain an overweight/overdimensional (OW/OD) permit from the KYTC Department of Vehicle Regulation. Annual permits are available for specific commodities, but most non-divisible loads require a single-trip permit. These permits specify the exact route the driver must follow to avoid low-clearance bridges or weight-restricted secondary roads. Kentucky enforces a 'no travel' policy for certain wide loads during holidays and specific hours in high-traffic areas like Louisville, Lexington, and Northern Kentucky. Escort vehicle requirements trigger when a load exceeds 12 feet in width or 75 feet in length on most two-lane highways.

Sources

Kentucky Transportation Cabinet - Motor Carriers (2024) — https://transportation.ky.gov/MotorCarriers/Pages/default.aspx Kentucky State Police Commercial Vehicle Enforcement (2024) — https://www.kentuckystatepolice.ky.gov/cve FMCSA Analysis & Information Online (2023) — https://ai.fmcsa.dot.gov/CrashProfile/Default.aspx ATRI Cost of Congestion and Delay Study (2023) — https://truckingresearch.org/

Frequently asked

Do I need to stop at a Kentucky weigh station if I am bobtailing?

Yes, all commercial vehicles with a gross vehicle weight rating (GVWR) over 10,000 pounds must enter Kentucky weigh stations unless they receive a bypass signal from an authorized electronic screening system. This includes empty trucks and bobtail tractors.

What is the fine for bypassing a weigh station in Kentucky?

Bypassing an open weigh station is a violation of Kentucky law and can result in a fine of approximately $250 to $500, plus court costs. KSP mobile units often patrol downstream of scales to intercept and return drivers who fail to pull in.

How much does a Kentucky KYU number cost?

There is no fee to apply for a permanent KYU number through the Kentucky Transportation Cabinet, but carriers must remain current on their quarterly weight-distance tax payments of $0.0285 per mile to keep the number active.

Are Kentucky weigh stations open 24/7?

Many major sites, such as the I-75 scales in Laurel and Scott counties, operate 24 hours a day, 7 days a week. Smaller scales or those on less-traveled routes may operate on a variable schedule determined by KSP CVE manpower.

What is the maximum width allowed without a permit in Kentucky?

The maximum width allowed on Kentucky's designated truck network without an overdimensional permit is 8 feet 6 inches (102 inches). Anything wider requires a permit and potentially escort vehicles depending on the total width.