Basis for Recommendation
To address the six known locations where the speed decreases from 75 km/h to 30 km/h on the DART network. It is noted that the speed decrease required a derogation with I-SIG-2145, Calculation of Signal Spacing Distance, however, given the events surrounding the Double SPAD event, there is some doubt as to its efficacy. As a result, the RAIU consider that the following safety recommendation is warranted:
IÉ-IM SET should undertake a review of I-SIG-2145, Calculation of Signal Spacing Distance, to consider if the risk approaches identified in the standard are effective in relation to the calculation of the spacing of signal distances, in particular, in relation to sharp speed decreases on the approach to signals and consideration should be given to incorrect driving techniques (i.e. driving into the bonds). A review of the use of derogations should also be undertaken.