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Recent research both in New Zealand and Australia has identified the benefits associated with the installation of various barrier types and in particular the significant benefits associated with wire rope barriers (WRBs). A result of that research will be an increase in the use of barriers and in particular WRB.

This research investigated the occurrence and corresponding maintenance costs associated with vehicle strikes on W-beam and WRB installations. The likelihood and cost of nuisance strikes have been evaluated in isolation from all-strikes as they result in significant maintenance costs on the state highway network. Nuisance strikes are events whereby the barrier is struck by a vehicle which is then able to drive away and the event is not recorded in the Crash Analysis System.

The environmental and operational variables that significantly influence the rate at which barrier strikes occur are determined in this research and a predictive spreadsheet tool has been developed to model the likely strike rate and maintenance costs associated with various barrier installation types. This tool is intended to assist practitioners with:

• the decision to install a barrier
• the selection of barrier type
• whether or not a carriageway or median should be widened to reduce future maintenance costs.

Keywords: barrier strike, maintenance costs, nuisance barrier strike, strike rate