Update, 2:45 p.m.: As the weather in Indianapolis has warmed up from brutally cold to slightly less cold, so has the temperature of pavement throughout the city.

Charnay Pickett, public information officer with the Indianapolis Department of Public Works, said as pavement temperatures have increased throughout Friday, road conditions also have improved.

"As the day has gone on, pavement temperatures have gone up, cars have been out driving along that salt, activating it, helping to melt the snow and move the snow," Pickett said.

Pickett added that 80 trucks are still out laying salt today, further attempting to clear roads ahead of commuters' drives home from work.

Update, 1:15 p.m.: With temperatures warming up to more than 25 degrees, Indianapolis drivers should be seeing improved driving conditions on interstates, said Mallory Duncan, a spokeswoman from INDOT.

Commuters faced slippery drives this morning and afternoon after a snowstorm blanketed Indianapolis overnight. The Indianapolis International Airport saw 1.8 inches of snow while Carmel, Fishers and other areas north saw up to 3.5 inches, National Weather Service Meteorologist Jason Puma said.

All of INDOT's vehicles are still out attempting to improve highways, Duncan told IndyStar.

Update, 10:15 a.m.: Snow stopped falling about five hours ago, and traffic is still a mess on most major roads in Central Indiana.

"We were out," said Betsy Whitmore, spokeswoman for the Indianapolis Department of Public Works. "Once it started to come, it kept coming at a high enough rate that you just have to keep plowing.

"It's going to take some time to get down to pavement."

Mallory Duncan, spokeswoman for the Indiana Department of Transpiration, said plow drivers were caught in the slow traffic, which has made it more difficult to clear the highways.

Who's to blame for slick roads? Science. Here's why.

All 60 of INDOT's Indianapolis-area trucks have been on the roads since 8 p.m.

"Our plows did the best they could and they are still out," Duncan said. "There's a lot more traffic on the roads in the morning."

Earlier: Central Indiana has certainly seen more snow in recent weeks, but the storm that hit overnight was timed just right to play havoc with the Friday morning rush hour.

What happened? The ground is too cold for the salt and the snow kept coming until just before most alarm clocks started going off.

"We knew it was coming," said Betsy Whitmore, chief communications officer for the Department of Public Works. "We laid some salt first, but as cold as it's been ... the salt takes longer to work."

Indianapolis deployed all 80 of its snow plows on Thursday afternoon. Except for a shift change at 11 p.m., the drivers have been on the streets ever since, Whitmore said.

Indiana State Police Sgt. John Perrine told IndyStar there have been "minor crashes everywhere" in Indianapolis this morning. With the roads as slick as they are, Perrine said this is no surprise.

A fatal crash involving an INDOT salt truck occurred around 6:15 a.m. near Monrovia, Perrine said. The truck was pulled over to the side of eastbound I-70 with its hazard lights on due to a mechanical issue when another vehicle struck the rear of the truck, Perrine said. The driver of the vehicle who hit the INDOT truck died.

Perrine tweeted at 9:02 a.m. that eastbound I-70 into Indianapolis "is a virtual parking lot," and that INDOT is "working dozens of crashes and traffic hazards in the area."

The Indianapolis International Airport saw 1.8 inches of snow while Carmel, Fishers and other areas north saw up to 3.5 inches, National Weather Service Meteorologist Jason Puma said.

"The snow fell throughout the night, ending right around rush hour," Puma said. "That doesn't give them a whole lot of time to clean things up."

After initially calling for delays, many schools began canceling all classes, including Washington Township, Pike Township and Carmel Clay Schools.

On the bright side, Puma said the snow has tapered off and temperatures are rising.

Central Indiana will see a high of about 30 degrees today. Expect highs in the 40s on Saturday and in the 50s on Sunday.

Call IndyStar reporter Vic Ryckaert at 317-444-2701. Follow him on Twitter: @VicRyc.