Crews say so far the presence of the three-strand cables is worth any slowdowns.

‘‘The tradeoff is worth the inconvenience,’’ said Bob Patterson, director of Emergency Medical Services at St. John’s Hospital.

St. John’s EMS crews aren’t seeing fewer crashes on I-44, but there’s been a significant decrease in their severity, Patterson said.

And when crews get the call to respond to an I-44 accident, they use gaps built into the cable system.

‘‘The guard cables make us plan our routes more carefully, but our computer dispatch center has programmed the crossovers into our system, and our vehicles have maps that show where the crossovers are.’’

Median guard cables work by snaring an out-of-control vehicle, stretching to absorb the car or truck’s force and preventing it from plowing headfirst into oncoming traffic.

Brian Chandler, traffic safety engineer with Missouri Department of Transportation, said designing frequent crossovers was the key to ensuring emergency vehicles can get to an accident. Prior to installing the cables, MoDOT studied whether delays could be an issue.

On Missouri interstates, there’s a gap every 2 or 2 1/2 miles to allow police, fire, ambulance or other emergency vehicles to cross over.

‘‘When they do need to respond, it can add some time, but not much,’’ Chandler said. ‘‘Police cars sometimes can drive down a median to get to an accident, but fire trucks and ambulances usually would go down to the next crossover to reach the site.’’

That might add a mile or two of extra travel.

‘‘If it’s a life and death situation, of course they can cut the cables and go through,’’ Chandler said. ‘‘But if it’s just involving property damage, no.’’

MoDOT began installing guard cables on I-44 in 2006 and has seen a big drop in crossover fatality crashes.

Chandler said that in 2005 — before guard cables were installed — 25 people died in cross-median related traffic crashes on I-44.

In 2006, 11 people were killed in crossover crashes on I-44 — mostly in places where the guard cables hadn’t yet been installed.

Through the first six months of 2007, only one person died in a cross-median crash on I-44, he said.

The cables have been so successful that MoDOT now plans to spend about $10 million a year adding them to non-interstate routes where crossover crashes have been a problem.

MoDOT is still working on prioritizing those additional sites.