This read-only value reports the previous (most recently completed) maximum round-trip delay measured for this circuit during the last measurement window, capturing the worst-case latency spike observed rather than a typical value. This is the figure an admin checks first when diagnosing intermittent latency complaints, since it reveals whether the circuit experienced a brief severe delay spike even if average latency looks fine. An engineer chasing a user complaint about occasional call quality drops on a voice PVC would check cktRtAccuMaxDelay for a spike well above the circuit's typical cktRtAccuAvgDelay.