Highway Accident Report

Adopted: February 27, 1974
U. S. 60-84,
DECEMBER 26,1972

NTSB Number: HAR-74/01
NTIS Number: PB-231852/AS


At 6:40 p.m., m.s.t., on December 26, 1972, a leased schoolbus-type vehicle carrying 34 persons was westbound on U.S. 60-84 about 10 miles east of Fort Sumner, New Mexico. A tractor-semitrailer carrying 4 cargo of cattle was eastbound on U.S. 60-84.

As the tractor-semitrailer approached a narrow bridge, the truckdriver observed the headlights of an approaching vehicle, which appeared to be on his side of the road. The truckdriver steered to the right, and the right side of the tractor contacted a crash cushion at the entrance to the bridge. The right rear wheel of the tractor mounted the bridge curb. The tractor snagged the bridge rail and began to rotate clockwise as the right wheels of the trailer struck and mounted the bridge curb. The truck jackknifed on the bridge and continued eastward into the path of the bus. Fourteen feet east of the bridge, the bus struck the left side of the tractor, which then disengaged from the trailer. The frontwall of the trailer crushed the bus rearward. Both vehicles came to rest against the guardrail 21 feet east of impact. No fire ensued.

Nineteen bus occupants, including the driver were killed. The 15 survivors suffered various types of injury. The truckdriver also survived.

The National Transportation Safety Board determines that the probable cause of the initial collision (truck/bridge end-post) was the failure of the truckdriver to keep his vehicle in its proper lane of travel on the highway. Factors that contributed to that condition were: (1) The influence on the truckdriver of two oncoming vehicles, (2) the absence and deceptive placement of light-reflecting traffic control devices, (3) the absence of a solid centerline on the bridge and its approaches, (4) the narrow width of the bridge deck, and (5) the truckdriver's concern that braking would cause his vehicle to jackknife.

The collision between the vehicles resulted from the engagement of the truck-tractor with the bridge end-post and interrupted surfaces of the rail which caused that vehicle to jackknife across and block both traffic lanes of the highway.

Contributing to some of the fatalities and to the severity of many injuries in the bus were

(1) the inadequate seat anchorage system and

(2) the absence of an integrated occupant restraint system such as seatbelts and highback cushioned seats.


The National Transportation Safety Board recommends that:

1. The Federal Highway Administration:

(a) Expedite development and implementation of a traffic-control system of positive guidance to assist drivers in remaining in the intended pathway at narrow highway structures. (Recommendation No. H-74-4)

(b) Restate more precisely the definition of narrow bridges in the Manual on Uniform Traffic Control Devices and determine its adequacy and applicability. (A redefinition should be consistent with the intended use of any signing plan devised under recommendation 1(a) of this report.) (Recommendation No. H-74-5)

(c) Require all States to bring approach guardrail sections at bridges on Federal-aid highways into compliance with the recommended installation described in the FHWA's Handbook of Highway Safety Design and Operating Practices. (Recommendation No. H-74-6).

(d) Expedite a program to improve, where feasible, substandard bridge-rail systems on existing bridges to increase resistance to pocketing or penetration by impacting vehicles of all classes and redirect those vehicles. Research, including crash testing, should also be expedited to develop criteria for mandatory standards for bridge-rail and guardrail designs for new bridge construction. (Recommendation No. H-74-7).

(e) Establish a program to identify and correct curb structures on existing bridges that create unnecessary hazards to the control of impacting vehicles. All new bridges should use railings that eliminate curbs. (Recommendation No. H-74-8).

(f) Develop a precise technical definition of crash cushions on the basis of minimum performance criteria. The factors defined should include not only classes of vehicles, but also velocities and angles of attack, so that standards can be established to require the most effective use of crash cushions on Federal-aid highways. Such standards would describe speeds and impact directions at which vehicle types will be adequately handled. (Recommendation No. H-74-9).

2. The National Highway Traffic Safety Administration:

(a) Proceed with the Notice of Proposed Rulemaking (Docket 73-3 Notice 1), to provide for (1) increased strength of scat anchorages which more fully uses the abilities of structures to protect passengers and (2) more protection against gross scat deflection which can permit seats to be carried away. (Recommendation No. H-74-10).

(b) Identify types of bus seat anchorages which are substantially below the strengths obtainable by such simple changes as substituting a bolt for a sheet metal screw. If it is possible to identify such buses by visual inspection, steps should be taken to inform owners of the possible change for local retrofit purposes. (Recommendation No. H-74-11).