The phrase "an additional spur" is correct and usable in written English.
It can be used when referring to something that provides extra motivation or encouragement to take action or to enhance a situation.
Example: "The recent success of the project served as an additional spur for the team to continue their hard work and innovation."
Alternatives: "a further incentive" or "an extra motivation".
A third pipeline to China is now being constructed, and an additional spur originating in Kazakhstan is also planned.
With United States unemployment stuck at 9.6 percent, some economists are arguing that the American economy needs an additional spur.
Appropriately, an additional spur track is planned for Elysian Fields Avenue, the setting for the 1947 Tennessee Williams play "A Streetcar Named Desire".
The researchers also attempt to estimate the economic cost of dengue—"Money talks," concludes Mr Shepard as an additional spur to policymakers to take action.
The huge sugar exports of the nearby island of Negros were an additional spur to its growth, and for a time Iloilo City rivaled Cebu City as the main port of the Visayas island group.
England have not become a poor side, as their performances in the second and third Tests showed, and there is no disgrace in losing to a side of such quality, arguably the best team to visit here since the 2005 Australia and minus their wicketkeeper and fulcrum Mark Boucher, injured so terribly before the series began: his loss clearly offered an additional spur.
Additional spur lines built since 1949 connect the industrial districts to the main trunk routes.
Pressure from America also appears to have increased under its new ambassador, Ronald Neumann.An additional spur has been the emergence of Abdul Rasul Sayyaf as one of the dominant forces in the new parliament.
It looks as if gains will be much lower in 2008, but a looming tax increase could easily spur an additional $500 billion in sales.
The European Commission estimates -- conservatively, in my opinion - that the digital revolution could spur an "additional 2.1percentt of GDP growth over the baseline".
Once built, the project to make water supplies more reliable would spur an additional estimated 19,600 jobs a year over 50 years, he said.
