Seagull islands are a common 'at-grade' treatment for three legged T-intersections used on high traffic volume roads and dual carriageways in countries such as Australia, New Zealand and the United States.
The aim of this research was to evaluate the effectiveness of high speed seagull intersections on WA roads located in the metropolitan area.
The research found that the treatment was effective on Marmion Avenue, reducing all reported crashes by 21.4% and casualty crashes by 62.4%.
The treatment could potentially also be effective on roads of similar conditions and characteristics, but there no definitive conclusion for roads with different conditions, pending the availability of more usable data for future research.
Road safety benefit:
This research was beneficial to the extent that it provides Government with a review of a potential counter-measure.
As there were difficulties with the assessment, the recommendations include:
- Better data keeping as to the location of this intersection type.
- Further research with larger data sets.
