This study investigates problems in the overall context of intracellular particle transport using coupled simple exclusion processes to construct mathematical models of systems under consideration. Nonequilibrium statistical mechanics and cluster mean-field theory are used to analytically solve the model steady state and derive phase diagrams and quantities characteristic of transport such as average density and entrance/bulk/exit currents. All results are supported by extensive Monte-Carlo simulations. Four systems are investigated, namely: A system where kinesin motor proteins jump between microtubule tracks due to a single-point inhomogeneity; a system where transport of kinesins on a microtubule is interrupted by a diffusive compartment; a system where kinesin transport on a microtubule is coupled to the aqueous medium surrounding it; and finally a system where dyneins are transported on two protofilaments linked to each other at every site.