To date, mesh network design theory has beendeveloped for the case where working and protectioncapacity is terminated at every node. It is recognizedthat express routes, which bypass some nodes en-route, would decrease the total DCS port costs but ithas been unclear how to incorporate bypass planning inthe optimal spare capacity design for a mesh-restorablenetwork. An important issue is whether the introduction of nodal bypass will increase the total sparecapacity needed for restorability, due to a reduction ofrestoration re-routing flexibility. To address thesequestions, we introduce the forcer concept for analysis of the relationship between workingand spare capacity in a mesh-restorable network. Weapply the forcer concept to show theoretically whybypass in fact need never require an increase in sparing and may actually permit a decrease in somecases. In tests to validate and exploit these findings,an average reduction of 12% in total spare capacity and16% in DCS port count totals were obtainedsimultaneously with an Integer Programming optimization. Thesesavings are relative to an already optimized fullyterminated network design. The work thus contributes togreater theoretical understanding and designcost-effectiveness for mesh-based restorable networks.