National Ready Mixed Concrete Association and its Truck Mixer Manufacturers Bureau (TMMB) affiliate question cost and weight factors attending a prospective National Highway Traffic Safety Administration (NHTSA) requirement that heavy-duty trucks bear stronger rear underride guards than presently compliant models. Preliminary estimates indicate the newer guards would add $307–$453 and 169–210 lb. to vehicle cost and weight, and represent $925 to $1,505 in life cycle fuel consumption.