The phrase "an important signpost" is correct and usable in written English.
It can be used to indicate a significant marker or indicator that guides understanding or decision-making in a particular context.
Example: "The study's findings serve as an important signpost for future research in this field."
Alternatives: "a crucial indicator" or "a key marker".
He said it was an important signpost to show where the world was heading in dealing with global warming.
OpenCourseWare was an important signpost that hammered home the point that the content of a university course was being rapidly commoditized by technology.
This album is definitely too long, and starts to meander into bonus-track territory just over the halfway mark, but marks an important signpost in her career.
"Services revenue growth was better than anticipated and is an important signpost for the stock," Ananda Baruah, an analyst at Brean Murray, Carret & Company, said in a note to clients.
The Tower was an important signpost to the development of Nine Elms from Vauxhall, with the wider Nine Elms development due to create 25,000 permanent jobs over the next 10 years".
Membership is also an important signpost that a country is on the way to achieving Western European standards of living, an important goal for a former Soviet republic like Estonia that has long been among the Baltic states eager to develop.
Although she regards the study as "a very important signpost paper," Cann suspects that our social behavior may be the key to our poor sense of smell.
His policies served as important signposts to his successors.
Someone asked Williams how many players would know the pillars and important signposts of the N.F.L.'s past?
Although there are additional questions about participatory community processes and community capacity to be explored, available evidence offers important signposts for how to accelerate progress in increasing the coverage of essential interventions for maternal survival.
Time after time, skilled leaders miss critical elements of a painting that send an important message, overlook signposts in a scene that speak to what's taking place, or can't figure out how to describe what's right in front of them.
