The team-trial event marked the start of the World championships in Toscana, Italy on Sunday.
"We are proud of what we did out on the road and it's easy to say now where we could have made up a second on the route, but the truth is we all gave our maximum and this time it just fell slightly short of the win," said South African Impey in his newsletter, referring to his Orica GreenEdge team.
"This is my first World Championship medal. I have had a great season this year and I look forward to finishing it off in a good way in my final race for the year being the Road World Championships this Sunday with Team South Africa."
Impey made Tour de France history in July 2013 by becoming the first African to take possession of the Tour de France yellow jersey.
The 29-year-old Impey was inserted in the Orica lead-out train in the 2012 Giro d'Italia as an "experiment". Matt Goss, the team's principal sprinter, was on a second-place streak and needed a win. Goss finally got the breakthrough the team was looking for by winning stage three.
Impey was a revelation for Orica-GreenEdge during the 2012 Tour, and this year, he's once again rolling the roads of France with the chief job description of being Goss's final lead-out for the line. – Sapa