The average total cost of a US domestic business trip rose 8 percent year over year to $1,073 during the third quarter, driven by a 16 percent increase in hotel costs, according to client spending data from Travel Leaders Corporate. The average nightly rate for US hotels paid by clients in the third quarter was $164, and the top 25 markets were split about evenly in being above or below that average. Domestic airfares were up 6 percent year over year but flat compared with the second quarter. The average car rental cost was $143, down from $165 in the third quarter of 2017. For international trips, hotel costs on an average trip were up 27 percent year over year in the third quarter, though that stemmed from longer trip lengths as well as rising rates. International airfares were up 3 percent year over year, and car rental rates were flat.