  We report molecular dynamics results for the contact values of the radial
distribution functions of binary additive mixtures of hard disks. The
simulation data are compared with theoretical predictions from expressions
proposed by Jenkins and Mancini [J. Appl. Mech. \textbf{54}, 27 (1987)] and
Santos et al. [J. Chem. Phys. \textbf{117}, 5785 (2002)]. Both theories agree
quantitatively within a very small margin, which renders the former still a
very useful and simple tool to work with. The latter (higher-order and
self-consistent) theory provides a small qualitative correction for low
densities and is superior especially in the high-density domain.
