Could very well have been caused by a culture gap. The article doesn't mention the victim's hometown, but this occurred in an urban area with heavy traffic. People in urban areas don't generally walk on the shoulders of highways, except for motorists whose vehicles are disabled. On the other hand, walking on the shoulder of a highway would be a an ordinary thing to do for a young man from a rural or exurban background. So he may have made a tragic error in judgment - assuming that there was no alcohol involved on the part of either the driver or the pedestrian.
But, again assuming no alcohol, why would the driver of the van would have been using shoulder at all?
A number of older highways (at least in my part of the country) have small or non-existant shoulders, but many of the newer roads/ highways have fairly wide highways that allow disabled vehicles to completely pull off the road and give walkers a fairly wide margin of safety.
It's late winter. Usually at that time the roads in the area are pretty beat up, and there's a fine assortment of mangled automotive parts and accessories on the shoulders.
Either might have caused either the driver or the walker to alter their path.