ObjectivesWith　the　rapid　development　of　expressways　in　the　mountainous　regions　of　southwestern　China,　closely　spaced　tunnel-interchange　structures　have　inevitably　emerged　due　to　topographical　constraints　and　environmental　limitations.　Given　the　unfavorable　road　geometry　and　rapid　cross-section　transitions,　drivers　face　significant　safety　concerns.　This　study　aims　to　investigate　drivers＇　safety　performance　at　closely　spaced　tunnel-interchange　sections　and　determine　how　safety　risks　can　be　mitigated　through　improved　traffic　control　devices　design.MethodsThirty-nine　participants　conducted　an　experimental　study　in　a　fixed-base　simulator.　The　test　scenario　was　modeled　on　the　Xingyan　Freeway-S3801　and　accurately　reproduced　in　the　simulator.　For　each　safety　performance　metric,　the　driving　simulator　experiments　yielded　a　dataset　with　780　observations.　To　address　the　idiosyncratic　variation　due　to　individual　driver　differences,　a　series　of　linear　mixed　effects　models　(LMM)　were　developed　to　analyze　drivers＇　behavior　responses.ResultsIn　closely　spaced　tunnel-interchange　sections,　a　general　impairment　of　both　longitudinal　and　lateral　performance　was　observed.　This　study　identified　potential　critical　impact　variables　in　traffic　control　device　systems.　According　to　the　LMM　results:　(a)　Removing　the　0.5　km　interchange　ramp　exit　advance　guide　sign　located　in　the　tunnel　exit　area　reduces　dangerous　behavior　in　the　corresponding　impact　area.　(b)　Replacing　the　0.5　km　interchange　ramp　exit　advance　guide　sign　with　arrow　pavement　markers　as　an　information　source　supports　improved　driver　performance,　promoting　driver　safety.　(c)　Adding　tunnel　exit　distance　signs　within　tunnels　is　recommended　to　enhance　situation　awareness　for　drivers.ConclusionsThis　study　addresses　the　scientific　issues　related　to　traffic　control　devices　setup　for　closely　spaced　tunnel-interchange　sections,　focusing　on　identifying　potential　critical　impact　variables.　The　findings　provide　guidance　on　the　design　of　traffic　control　devices　for　such　sections　and　support　revisions　to　national　engineering　standards.