The scaling of copper wires and the increase in signal switching speed produce transient crosstalk coupling between interconnect lines, which causes overshoots and additional time delay. The time-domain analysis of CMOS gates driving next-generation interconnects consisting of single wall carbon nanotube (SWCNT) bundles or multiwall carbon nanotubes (MWCNTs) is carried out. Accurate simulation models of SWCNT bundles and MWCNTs are proposed in the frequency domain by using both the multiconductor transmission line (MTL) formulation and the multiequivalent single conductor (MESC) approach. The fast transient voltage responses of two coupled nanointerconnects of 14 and 22 nm technologies to a pulsed input are computed by means of both the MTL and the MESC models. The obtained results are in good agreement. The same agreement is achieved by computing the 50% time delay of the output voltages.