The Ohio State University

Turfgrass science research often incorporates the use of traffic simulators or wear machines that produce traffic damage commonly seen on sports surfaces. Over the last 60 years, all kinds of machines have been developed, from golf carts to modifed rollers and core aerators.

Most traffic machines are based on a pull-behind or walk-behind roller system that has a differential slip (DS). The rollers are typically equipped with soccer. golf or football cleats and they apply both vertical and horizontal forces to the turf, which in turn causes turf shearing, scuffing and displacement. There is also some degree of soil compaction caused, depending on the soil type and traffic intensity. There are other traffic machines that do not have the differential slip mechanism, such as the modified sweeper/paddle machine used at Rutgers, used to create plant tissue damage without causing soil compaction.

With so many machines being used by so many research programs it is difficult to work to a national standard and to a national scale. Some research papers may discuss traffic as being "heavy", while others refer to percent ground cover lost or kgs force applied to the turf. One of the standard scales used is based on the Brinkman DS traffic simulator, whereby two passes with the machine is equal to 1 NFL game at the 40-yard line. The scale quantitively measures the amount of cleat marks per square foot. This scale is helpful in that it can be replicated by all other kinds of DS machine.

This is the main reason OSU invested in the SISIS DS machine, developed at the Sports Turf Research Institute (STRI) in England. The machine can be used to produce varying intensities of wear and the cleat damage can be easily compared to similar types of DS machine.

The good news is that the National Turfgrass Evaluation Program (NTEP.org) and the Sports Turf Managers Association (STMA.org) have teamed up to fund sports turf research on traffic tolerance and to try and set some national standards. This research will hopefully start in 2009. In the meantime, each of the turgrass science programs across the USA will do their best to draw parallels with each others traffic research.