As previously noted, Trailways (unlike Greyhound) was an association of independent companies operating under the same banner for advertising purposes. Burlington and Santa Fe led in the formation of the association in 1936.
The first blotter advertises two daily buses operating about twelve hours apart between Chicago and California. While they competed against the Burlington’s own trains, they probably served smaller towns and (despite the “fastest time” claim) took several hours longer than the Exposition Flyer. Judging from the image of a bus on the blotter, this was probably issued around 1937 as the various Trailways companies began acquiring more streamlined buses in 1938.
This blotter shows a PD-3701 bus that General Motors began making in 1941. Called “Silversides” for their fluted stainless steel siding, most of these buses went to Greyhound. However, Burlington was able to buy some as a good customer of General Motors locomotives (not to mention the pioneer of fluted stainless steel), and it called them DieseLiners, an obvious play on the word streamliners.
This ad that appeared in a Des Moines newspaper in 1945 touts the benefits of riding a DieseLiner as opposed to driving. One endorsement notes that “my home town can be reached only by bus,” again suggesting that they were marketing to people in small towns where Burlington trains did not stop.
Another ad from the same year that appeared in a Salt Lake City newspaper announces faster bus service. The first blotter above indicates that pre-war buses took about 8 hours longer to get from Salt Lake to Chicago than the Exposition Flyer, so (assuming there were no wartime slowdowns of bus service) a 14-hour reduction in time would make the bus faster than the train.