Two growing populations, people and panthers, are colliding with increasing frequency every year in Florida. It's not hard to guess which is coming off worst - Eleven of the endangered cats were flattened by drivers last year. It was a record toll on one of the state's rarest animals and a serious bite out of a species numbering perhaps 100 adults in the wild.

The prime kill zone proved to be Southwest Florida, centered around a handful of rural roads in eastern Collier County. That area accounts for close to half the state's 58 panther roadkills since 2000, according to a study by the University of Central Florida.

The number of panther deaths has risen from 8 in the 1990's to 24 in the last 6 years. Whilst every carcass probably isn't found, vehicles are the leading cause of documented panther deaths over the past six years, claiming roughly 10 percent or the adult population annually.

The county and two developers have agreed to speed up construction of at least five wildlife crossings. These are a combination of roadside fencing and strategically located underpasses for animals.

Near extinction a decade ago with as few as 30 adults weakened by in-breeding, the panther population has rebounded thanks largely to a cross-breeding program with Texas cougars. They've slowly but steadily multiplied to an estimated 80 to 100.

The main problem is space - there isn't enough of it in the area. Male panthers typically prowl 200-square-mile territories. State and federal agencies contend they lack power to control habitat loss, the cat's biggest threat.

Federal Recovery Program

A new federal recovery pins the panther's best hope on establishing cats far from the core population in Southwest Florida, either by creating protected natural corridors to ease movements or by ''translocation'' - trucking cats to other promising locales in the state.

Despite studies showing they can sharply reduce roadkill, installing wildlife crossings on existing roads typically takes a lot longer and costs a lot more.

The study focused on 8 months where 333 roadkills of 59 species on just three roads were catalogued.

The area is now becoming overcrowded for the panthers. More cats will seek new territory. Strays already have been found near Tampa and as far north as Flagler County.