The　damage　of　expansion　joints　is　a　common　problem　of　bridges,　which　adversely　affects　not　only　driving　comfort　and　safety　but　also　the　durability　of　the　structure.　Jointless　bridges　can　fundamentally　solve　this　fragile　problem.　However,　how　to　accurately　assess　its　environmental　and　economic　benefits　has　not　been　studied,　specifically　as　climate　change　intensifies.　To　address　these　issues,　this　study　first　examines　the　effects　of　climate　change　on　design　expansion　allowance　of　bridge　expansion　joints　based　on　climate　projections.　Subsequently,　the　life-cycle　environmental　and　economic　benefits　of　two　jointless　bridges　located　in　Beijing–Hong　Kong–Macau　Expressway　are　quantified　under　climate　change　scenarios.　Moreover,　uncertainty　and　random　forest　algorithm-based　importance　analyses　are　carried　out　to　help　decision-makers　identify　major　environmental　and　economic　factors　and　develop　eco-friendly　plans　to　facilitate　jointless　bridge　construction.　Results　indicate　the　following:　(1)　the　design　expansion　allowance　of　bridge　expansion　joints　tends　to　increase　with　the　time-dependent　temperature　and　humidity;　(2)　the　avoidance　of　traffic　detours　caused　by　the　maintenance　and　replacement　of　expansion　joints　is　a　major　source　of　life-cycle　environmental　and　economic　benefits;　(3)　traffic　detour　distance　is　the　most　important　factor　influencing　the　life-cycle　environmental　and　economic　benefits.　©　2021　Informa　UK　Limited,　trading　as　Taylor　&　Francis　Group.