We study the low-temperature properties of linear Josephson-junction arrays capacitively coupled to a proximate two-dimensional diffusive metal. Using bosonization techniques, we derive an effective model for the array and obtain its critical properties and phases at T=0 using a renormalization-group analysis and a variational approach. While static screening effects given by the presence of the metal can be absorbed in a renormalization of the parameters of the array, backscattering originated in the dynamically screened Coulomb interaction produces a nontrivial stabilization of the insulating ground state and can drive a superconductor-to-insulator transition. We study the consequences for the transport properties in the low-temperature regime. In particular, we calculate the resistivity as a function of the temperature and the parameters of the array, and obtain clear signatures of a superconductor-to-insulator transition that could be observed in experiments.