Pounding　between　adjacent　bridge　structures　was　frequently　observed　in　previous　major　seismic　events.　This　paper　proposes　using　inerter-based　dampers　(IBDs)　to　preclude　pounding　damage　between　adjacent　bridges,　and　comprehensively　investigates　their　optimum　designs　and　control　performances.　Specifically,　four　classical　IBDs　are　investigated,　including　tuned　inerter　damper　(TID),　tuned　mass　damper　inerter　(TMDI),　tuned　viscous　mass　damper　(TVMD),　and　spring　dashpot　inerter　system　(SDIS).　Analytical　models　of　adjacent　bridges　equipped　with　these　IBDs　are　developed,　and　corresponding　equations　of　motion　are　derived.　Three　control　objectives　are　defined,　and　the　numerical　search　method　is　utilized　to　determine　the　optimum　design　parameters　of　IBDs　for　each　control　objective.　In　addition,　sensitivity　analysis　is　performed　to　demonstrate　the　robustness　of　IBDs　against　the　uncertainties　from　their　actual　design　parameters.　Finally,　the　control　effectiveness　of　IBDs　under　various　excitations,　including　the　white　noise　and　natural　seismic　events,　are　investigated　and　compared　with　each　other.　The　results　show　that　the　introduction　of　IBDs　could　reduce　not　only　the　relative　displacement　between　the　adjacent　bridges　but　also　the　displacement　and　acceleration　responses　of　each　individual　bridge;　the　TVMD　and　SDIS　are　more　effective　than　the　TID　and　TMDI　with　the　same　inertance,　but　the　TID　and　TMDI　can　achieve　optimal　performance　with　smaller　damping　ratio.　In　addition,　the　control　forces　of　the　optimal　TID　and　TMDI　are　smaller　than　those　of　the　TVMD　and　SDIS　with　the　same　inertance　ratio.