Highway post offices, built on bus chassis, were a noble experiment in the 1940s. Their function was to allow postal clerks to sort mail enroute toward a general destination. This provided a faster level of service than could be provided by sorting mail at stationary points and then moving it in closed bags to the destination post office.

The era of the highway post office bus was short lived, spanning the years from just prior to World War II to the early 1970s. The concept of sorting enroute in buses failed for exactly the same reason that the railway post offices failed. Both did well in serving cities and towns along a comparatively straight line. But by the late 1950s, America was no longer built along straight routes. Rather, our communities developed into a fan shaped pattern, especially around major metropolitan areas. There could never be enough highway units to serve them all. For this very reason, the regional centers were born. They serve not only as depots for long haul service by air, but for local distribution as well, all of which is hauled by trucks.

The Museum's HPO bus was built by the White Motor Company in the early 1940s, and was used in the 1940s and 1950s.

Statistics:

• Model: 789
  
• Engine: Model 24A, 12-cylinder, horizontally opposed
  
• Horsepower: 210