The health of a first world economy can often be measured by how busy its rail system is kept, and these individuals work hard to ensure nothing gets de-railed. They may be the engineers and conductors controlling trains, repair staff maintaining the engines, yardmasters ensuring the content of cars. or switch operators determining who goes where.
Pilots and air traffic controllers are well known as the Yin and Yang of air travel. The professionals in this audience focus on overseeing the safety of customers by directing their collective aircraft to their safe destinations. They may be seen researching airlines like American Airlines or United via job sites or enjoying content related to Air Traffic Controllers (such as the forum StuckMic)
Truck driver. Teamster. Truckie. Lorry driver. They go by many names, but these individuals represent a significant chunk of all road traffic and are represented by numerous large transportation companies (in addition to independent agents) such as Con-Way, Swift Transportation, R & L Carriers, and C.R England, to name only a few.
Don't call them stewardesses. These individuals oversee the safety and comfort of customers on aircraft by offering safety demonstrations, conducting preflight inspections, and maintaining order at 30,000 feet. They may have been seen researching airlines like American Airlines, United, or Frontier Airlines as potential employees or consuming content related to the job.
Economies of today exist at a scale that precludes storing your inventory behind the counter and delivering them by a horse like pappy did at his general store. These individuals handle the logistics and warehousing of the aforementioned goods, including providing transportation of cargo and handling customers. They may be allocating materials and cargo or storing them in warehouses or dealing with inventory control. They may have been seen researching companies like UPS, J.B. Hunt, and Ryder Supply Chain Solutions.
These individuals have "tasted flight and walk the earth with their eyes turned skywards", though unlike Da Vinci, their longing is more likely for a paycheck than the air itself. Pilots are the human face of air travel, and whether they come from a military or civilian background, you'll need one to get your 747 or Cessna off the ground. They may have been observed consuming content related to professional flying or interacting with websites related to pilot jobs.