Navigational Traffic Conflict Technique: A Proactive Approach to Quantitative Measurement of Collision Risks in Port Waters

Abstract

Navigational safety analysis relying on collision statistics is often hampered because of low number of observations. A promising alternative approach that overcomes this problem is proposed in this paper. By analyzing critical vessel interactions this approach proactively measures collision risk in port waters. The proposed method is illustrated for quantitative measurement of collision risks in Singapore port fairways, and validated by examining correlations between the measured risks with those perceived by pilots. This method is an ethically appealing alternative to the collisionbased analysis for fast, reliable and effective safety assessment, thus possesses great potential for managing collision risks in port waters.

Modelling Port Water Collision Risk Using Traffic Conflicts

“…A serious conflict corresponds to an encounter that may pose risk of a certain collision, i.e., collision cannot be avoided by taking any kinds of evasive actions. In this research, the serious conflicts are defined by using a set of threshold values, which were developed by Debnath and Chin (2010). The threshold values were defined by utilizing a risk scale that represents different risk levels, which were described by the level of actions necessary to avoid a collision.…”

“…A map showing the fairway sections is presented in Figure 1. The response variable of the model is the collision risks in the fairway sections for day and night conditions, which are measured by the NTCT (see Debnath and Chin, 2010 for details). The explanatory variables include the geometric, traffic and regulatory control characteristics of the fairway sections and a time indicator.…”

Modelling Collision Potentials in Port Anchorages: Application of the Navigational Traffic Conflict Technique (NTCT)

“…Collisions in port waters account for a major share of the all port-water accidents involving vessels (Goossens and Glansdorp, 1998;Akten, 2004;Darbra and Casal, 2004;Yip, 2008). A number of researchers (e.g., Debnath and Chin, 2007;Chin and Debnath, 2008;Chin et al, 2010;Debnath and Chin, 2010;Weng et al, 2012) have contended that navigational collisions would remain a major concern for many seaports due to a rapid increase in the numbers and sizes of vessels in many navigational areas (Soares and Teixeira, 2001). …”

“…As an alternative to the historical data, recently some researchers (e.g., Debnath and Chin, 2006;Debnath and Chin, 2010;Montewka et al, 2010;Debnath et al, 2011;Weng et al, 2012;Li et al, 2014) have looked at surrogate indicators of the collision events, such as navigational traffic conflicts and close encounters between vessels.…”

“…The safety analysis approach based on the surrogate indicators of collisions is appealing, because it overcomes the major limitations of the traditional approach that relies on historical collision records. Debnath and Chin (2010) have discussed this issue in detail in their article which introduced a novel and proactive approach for measuring the risks of collisions, namely the Navigational Traffic Conflict Technique (NTCT). The NTCT utilises traffic conflicts as an alternative to historical collision records, thus it allows managing collisions in a proactive manner.…”