Concentrating air traffic in between communities can decrease annoyance. With this in mind, a trial started on November 22nd 2007 to concentrate traffic in between the communities of Hoofddorp and Nieuw-Vennep: the CROS Pilot 3b. The route makes use of the radius-to-fix navigation technique (also known as a RF-leg). In the CROS Pilot 3b'+ project the position of the turn is optimised to improve the noise annoyance reduction.
The challenge
The CROS Pilot 3b has significantly improved the overall annoyance in the area. Locally however an increases in noise occurred resulted from the change. The KDC project CROS Pilot 3b'+ investigates the potential to improve the location of the radius-to-fix turn of the CROS Pilot 3b to further reduce the noise annoyance in the area.
The approach
Three proposals to improve the route have been made in the form of alternate route designs. The most promising two designs were evaluated on the effects on environmental impact (including noise) through noise studies. Additionally the variants were visualised.

The results
The results of the project have been presented at the residents meeting of the municipality of Haarlemmermeer in November 3rd 2009 (see news article). The results of the noise calculations and calculated environmental impact of the alternative routes were explained and discussed. Furthermore computer animations of the route alternatives were presented. They can be replayed blow.
Animation 1: A comparison of the traffic dispersion and location without RF-leg,
with current RF-leg (CROS Pilot 3b) and the two optimised route alternatives
Animation 2: A simulation of instantaneous noise levels of an average departure on the current CROS Pilot 3b RF-leg
Animation 3: A simulation of instantaneous noise levels of an average departure on the route alternative, variant 1
Animation 4: A simulation of instantaneous noise levels of an average departure on the route alternative, variant 2
After research, the municipality of Haarlemmermeer has announced during the plenary meeting of CROS in november 2009 to refrain from the wish for a wider radius-to-fix turn because of the associated shift of noise annoyance.
Parties involved
AAS, KLM, LVNL, DGLM, To70, CROS




