Abstract: 

When considering mode choice criterion, departing air passengers allow a period of time, additional to the time allowance predicted for their ground access to airports. This additional time is commonly known as a "safety margin". The safety margin allowance increases the possibility of arriving at the airport no later than passengers' preferred arrival times. This study is the first to assess the magnitude of safety margin allowed for airport ground access trips. With the use of revealed preference survey data, the effects of safety margin allowances on ground access mode choices to Hong Kong International Airport (HKIA) are quantified by a multinomial logit-type mode choice model. The model results indicated that, when compared to non-business air passengers, business air passengers place a significantly higher value on both travel time and safety margin for their ground access to HKIA. The findings of this study provide valuable information to various transport operators for their design and improvement on airport related traffic.