Buffalo Grove is taking a harder look at five intersections that accounted for the most crashes over the past year, including a surprising one that took the top spot.

Buffalo Grove Road and short Aptakisic Road — the small strip of roadway between McHenry Road and Buffalo Grove Road south of Lake-Cook — was the worst intersection of the year, logging 17 crashes alone.

Buffalo Grove and Aptakisic roads, Lake Cook and Arlington Heights roads, Arlington Heights and McHenry roads, Lake Cook and Buffalo Grove roads and Arlington Heights and Dundee roads logged 56 crashes together in 2011.

Police officials aren’t sure yet what caused Buffalo Grove and Aptakisic to skyrocket from not even making an appearance in the top 10 to taking the top spot, but they will be studying all five roads this year and devising interventions to lower crashes, said Sgt. Scott Kristiansen with the Buffalo Grove Police Department’s traffic unit

Buffalo Grove’s crash reduction methodology has helped lower the number of crashes in the top five intersections, which vary annually, by about half over 10 years, Kristiansen said.

Recent data shows there were 86 crashes in the top five intersections in 2004, which were reduced to 50 crashes in 2010.

The traffic division spent last year focusing on the top five intersection of 2010, a list topped by Buffalo Grove and Lake Cook roads, and including repeat offenders such as Arlington Heights and McHenry roads, Arlington Heights and Lake Cook roads, McHenry and Lake Cook roads and Buffalo Grove and Dundee roads.

After the patrol division researches the top crash sites for a particular year, they drill down into the data and discover when they frequently occurred, what type of crash happened and what traffic codes may have been violated, Kristiansen said.

They then test out which method might be the most effective for reducing crashes in each intersection.

Police were able to take the Buffalo Grove and Lake Cook intersection from the top spot in 2010 to the fourth spot in 2011 using a drone car.

“We learned the best way is through presence, not necessarily ticket-writing,” Kristiansen said.

The car sits near the intersection and reminds drivers to watch themselves, and particularly to not rush through a light when traffic is sitting on the other side, which often leads to rear-end crashes around the intersection.

Arlington Heights and McHenry roads intersection was a different story. Analysis found that most of those crashes were from motorists running red lights.

Police keep a presence at those roads and write tickets for those running red lights. They have gone so far as to dress up like solicitors asking for donations in order to covertly report those running the lights, Kristiansen said.

“People have to know we’re watching the intersections,” he said.

Sometimes police recommend an engineering solution, such as making left turns illegal into a shopping center or school parking lot, to reduce the number of crashes.

Overall, crashes are at a 20-year-low and Kristiansen believes much of that is due to police efforts, particularly because the village has expanded significantly in that time, bringing a lot more cars on the road.

They are now evaluating the problems at the top five worst intersections for 2011 and will soon deploy methods to reduce those numbers.