Municipal type bridges are being improved to be more cost-effective, durable, and easy to maintain. New designs and processes are being used to extend the lifespan of old timber bridges, allowing them to handle heavier traffic until they can be replaced. Some of the new designs include 'spir-l-ok' or 'hel cor', large rc pipes, slab linked large rc box culverts, 'fabriform' jacketting of timber piles, and reinforced concrete overlay of timber bridge decks.