Constraining the dependence of the dense nuclear matter equation of state (EOS) on baryon density is a long-standing problem of nuclear physics. Despite active development in recent years, it is still a challenge for theoretical approaches – primarily hadronic transport simulations – to set constraints on the nuclear matter EOS at high baryon densities using the old (AGS, GSI), recent (RHIC BES FXT, HADES, NSCL), or future experimental results (FAIR, FRIB) on ratios of charged pions, neutron and proton yields and differential flow, charged particle flow, spectra, and femtoscopic correlations. Moreover, the new experiments not only measure these traditional observables with higher precision (and, in some cases, with radioactive beams), but they will also study new observables sensitive to the EOS, such as fluctuations and correlations.