June 19 (Bloomberg) -- Karl Lagerfeld, the head designer at Chanel with a penchant for ultra-slim suits and black leather gloves, slipped on a yellow reflective vest to convince the French that road safety was more important than chic.

Lagerfeld agreed to pose in the shapeless protective apparel as part of a French government safety-awareness campaign, which was kicked off yesterday. The vest and a reflective triangle will become mandatory for all drivers and cyclists on July 1.

``It's yellow, it's ugly, it doesn't match anything, but it can save your life,'' says the poster, featuring Lagerfeld wearing the vest and his customary deadpan expression accentuated by dark sunglasses.

The number of traffic deaths in France jumped 10 percent to 346 in May, the highest since the beginning of the year, the Ministry of Environment said on its Web site. Two cyclists have died in Paris since the introduction of free municipal bicycles last year.

While the law comes into effect on July 1, drivers will get a three-month grace period after which they will be fined 135 euros ($209), the Ministry said.

To contact the reporter on this story: Ladka Bauerova in Paris at lbauerova@bloomberg.net.

Last Updated: June 19, 2008 06:24 EDT