What’s Happening?

The NASCAR Cup Series heads to Kansas Speedway this weekend, a track with a unique construction. The corners have variable banking, and it makes a major impact on the racing at the track. How does variable banking affect racing at NASCAR Cup Series tracks?

• Kansas Speedway opened in 2001 with 15 degrees of banking in the corners. The track was reconfigured in 2012 to include variable banking, otherwise known as “Progressive banking”.
• Kansas is not the first track to include variable banking. Homestead-Miami was the first track to implement it in 2003, other tracks have attempted it since.
• Fans generally like variable banking. It helps produce multi-groove racing, and fans have a lot of fun with variable banked tracks.

The Background of Variable Banking

In its simplest definition, variable banking means different banking angles around the track. By that definition, virtually every race track has variable banking, but, in this context, it’s a little different.

Variable banking at a track like Kansas means the banking angle varies from lane to lane at a specific point on the track, usually the corners. At Kansas, for example, the bottom lane is 17 degrees with the banking slowly getting steeper until the 20 degrees of banking up against the wall. Since the banking progressively gets steeper the further up the track, this type of banking is often called”Progressive banking”.

Variable banking is a relatively new idea at race tracks. New Hampshire Motor Speedway first implemented it in 2002, but, Homestead-Miami Speedway was the first to perfect it. Homestead was originally flat, but, the banking changes gave the track an entirely new life.

Other tracks began to follow suit. Iowa Speedway was built with progressive banking in 2006. Bristol tried to input it in 2007, but, it only lasted until 2012. Phoenix Raceway (2011) and Kansas Speedway (2012) were the last two tracks to implement it in their reconfigurations. Why did these tracks implement it?

How Does It Affect Racing?

The goal of this type of banking angle is to create multiple grooves from day one. Since the high line is a slightly longer trip around the track, the bottom lane tends to be the preferred groove, particularly when tracks are first repaved. Look at the 2017 Texas race as an example.

Single-groove tracks struggle to put on good races, particularly on high-speed tracks. With the negative effects of dirty air at high speeds, tracks with one racing groove can devolve into glorified high-speed parades.

Variable banking produces multiple grooves from the start by mitigating the detractors of racing in the upper lane. Since the high lane has more banking, drivers can carry more speed to make up for traveling a further distance, which gives them a big run down the straightaway. The bottom lane still allows drivers to dive deep into the corner, giving them a big advantage on corner entry.

While progressive banking doesn’t allow drivers to race all over the track from day one, it does give drivers more options. The 2009 Xfinity Series race at Iowa is a good example of this.

However, the variable banking begins to shine more as the track surface wears. The high line often becomes the preferred line at progressively banked tracks due to being able to carry more speed. Homestead-Miami is a perfect example of this.

Variable banking is a part of a few NASCAR tracks, and it produces a unique style of racing. It will be on full display at Kansas Speedway this weekend.