Sharing Two-Lane Highways with Farm Equipment on US 90 and FM Roads

Posted by Jerry Dennis on Aug 8th 2026

Sharing Two-Lane Highways with Farm Equipment on US 90 and FM Roads

West of Loop 1604, the road changes. US 90, FM 471, FM 1957, and the farm-to-market roads around Castroville, La Coste, and Hondo carry tractors, cotton modules, hay trailers, and implements that may be moving 15–25 mph with a vehicle doing 70 coming up behind them.

This is everyday Medina County driving — and it is one of the skills city-trained teens are least prepared for. A new driver who only practiced on Culebra or I-10 can panic when a wide header appears over a rise.

How to recognize slow-moving equipment

  • The orange-red SMV (slow-moving vehicle) triangle on the back is required for equipment designed to travel 25 mph or less.
  • Flashing amber lights, oversized mirrors, and a cloud of dust or chaff are early clues.
  • At dusk the triangle and lights can be the only warning you get before the shape of the machine is clear.

Passing rules that keep people alive

  1. Slow down early. Do not close the gap at highway speed and then decide.
  2. Pass only in a marked passing zone with a long, clear sight line. Blind hills and curves on US 90 west of Castroville are not the place to gamble.
  3. Account for width. Some implements are wider than a lane. You may need the entire left side of the road.
  4. Do not linger in the no-zones beside a tractor. The operator’s view to the right and rear is limited.
  5. After you pass, do not cut back until you see the entire machine in your rear-view mirror.
  6. Never pass on the shoulder. Soft caliche and hidden driveways make that a rollover risk.
  7. If you cannot pass safely, drop back and wait. Thirty extra seconds is not a failure.

When equipment turns

Farm equipment often turns into unmarked field drives. A left-turn signal on a tractor can mean a wide swing. Stay back until the turn is complete. Honking rarely helps; the operator may not hear you over the engine.

If your teen will commute on Highway 90 or FM 471, ask us to include rural two-lane practice in their behind-the-wheel hours. City miles alone do not cover this.

Safer Roads with Rhodes!