Travel　time　reliability　(On-Time　Arrival)　is　an　important　evaluation　indicator　of　urban　road　traffic　service　quality.　However,　traditional　travel　time　reliability　evaluation　frequently　ignores　traveler＇s　actual　perception.　This　research　defines　the　concept　of　travel　time　reliability　of　car　commuters　as　the　probability　that　car　commuters　complete　the　trip　within　an　expected　travel　time　between　a　given　origin　and　destination.　The　research　seeks　to　establish　a　simple　and　effective　expected　travel　time　model　of　car　commuters　based　on　actual　revealed　preference　survey　data.　The　results　illustrate　that　expected　travel　time　is　equal　to　1.38　multiple　travel　time,　and　expected　travel　time　model　prediction　accuracy　is　better.　Afterward,　analysis　of　travel　time　reliability　of　road　based　on　video　monitor　data　in　Beijing.　Car　commuters　are　more　adaptable　and　tolerable　to　traffic　congestion　than　common　cognition.　The　research　reveals　that　the　travel　time　reliability　calculation　result　based　on　the　expected　travel　time　model　of　car　commuters　is　more　consistent　with　the　traveler＇s　actual　perception.　The　research　opens　up　new　possibilities　for　urban　road　traffic　service　quality　accurate　evaluation　and　effective　improvement,　which　is　based　on　the　expectation　and　tolerance　of　the　traveler＇s　actual　perception.　©　2021　Proceedings　of　the　25th　International　Conference　of　Hong　Kong　Society　for　Transportation　Studies,　HKSTS　2021:　Sustainable　Mobility.　All　Rights　Reserved.