Scan chain insertion can have large impact on routability, wirelength and timing. We propose a routing-driven and timing-aware methodology for scan insertion with minimum wirelength. We take into account timing slacks at all sinks that are affected by scan insertion, to achieve a scan chain ordering that meets timing and has smallest wirelength. For the case where sink timing is not met, we also propose a buffer insertion methodology with minimum wirelength objective. The key contribution of this paper is a method to compute a timing-driven incremental connection suited to scan insertion; this has possible applications in general incremental routing.