Quick Answer: Avoid keyword cannibalization by giving every location page a unique search intent, not just a swapped city name. Build a strict page architecture where each URL targets one primary term, one primary service-area modifier, and a distinct supporting content set; then control internal links, canonicals, and indexation so Google can clearly see which page is authoritative for each query.
When you scale hundreds of location-based programmatic pages, cannibalization usually happens because multiple URLs are optimized for the same keyword cluster, same intent, and same internal link signals. The fix is to design the site like a taxonomy: assign a single canonical page for each combination of service + geography, differentiate pages with localized proof points, FAQs, pricing or operational details, and use template rules that vary title tags, H1s, body copy, schema, and internal anchor text by market. You should also monitor Search Console for overlapping queries, consolidate duplicate intent pages, and use noindex or canonical tags only when a page exists for utility rather than rankings. The goal is not to create many pages—it is to create many clearly distinct ranking targets with non-overlapping intent.