One of the most important bottlenecks that contributes to the congestion of traffic is nonoptimal traffic signal control. Techniques that have been investigated to optimise traffic signal control have been focused on improving the traffic flow through individual intersections. However, if intersections are optimised based on only reducing local congestion, this could result in introducing congestion in other places. Therefore, this paper introduces a normal form game that can be used to analyse the impact on local and global performance when optimising traffic signal control. Results obtained from a realistic traffic simulation suggest that it is sometimes possible for each player to choose a traffic signal control strategy that optimises its own welfare but also maximises the social welfare. The results also indicate that sub-optimal traffic signal control strategy profiles can become optimal when exposed to certain traffic intensities.