Date: 202010
Local time of day: 1201-1800
Location: DWH.Airport, TX
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Small Aircraft
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Taxi
ATC / advisory: Ramp DWH
Reporter organization: Personal
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Distraction; Confusion; Situational Awareness
Anomaly: Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Excursion Ramp; Ground Incursion Taxiway
Detector: Person Flight Crew
When detected: Taxi
Contributing factors: Airport; Human Factors; Procedure; ATC Equipment / Nav Facility / Buildings
Primary problem: Procedure

Narrative: The issue arose when I was taxiing from the northernmost T hangars to Ramp C at DWH to perform a run-up before a VFR departure for a local flight. Several corporate jets were parked on Ramp C and upon entering my aircraft I could hear a jet engine running; but I couldn't tell which aircraft it was. Ramp C is where run-ups are performed on the north end of DWH; and I needed to taxi to the south end of Ramp C in order to access an open spot for run-up; however the way I was familiar with was blocked by a pickup-truck. I then elected to turn right on N and taxi north then turn left on Ramp C. There is normally room to taxi behind aircraft parked on that ramp; but because one of the jets was running at least one engine; it wasn't safe to taxi behind them. I then elected to taxi south on Ramp C in front of the parked jets; and as I did so I saw that there were people walking in front of them; and also a vehicle approaching them from the south; so I swung out wide to give plenty of clearance; proceeded to an empty spot; and performed a run-up. On my initial taxi out for the run-up I didn't see the white boundary line of Ramp C; and assumed that I was safely inside of it; based on my previous study of the Jeppesen airport diagram. However Ramp C does not extend out as far toward Taxiway P as it appeared on the diagram. This was only my second time operating out of the north side of the airport; and my first time taking this route at the north end of Ramp C; and unfamiliarity was a factor. I chose this route instead of taxiing around the south end of Ramp C because the way was blocked by a pickup truck. The area is very congested; and the airport is poorly marked. Many of the ground markings; taxi lines; etc. are faded. Additionally; many ground vehicles; such as the airport vehicle; fuel trucks; golf carts; and other vehicles for pilots; passengers; employees; and residents that live on the field routinely drive on some of the ramp and taxiways without communicating on the radio; blurring the lines between the movement and non-movement areas. Specifically fuel trucks and the official airport vehicle (marked with signage on the doors) operate on taxiway P without making radio calls. Though I didn't realize it at the time; it was when I swung wide while heading south on Ramp C that I feel I may have encroached into taxiway P. It was upon completion of the flight when taxiing back to the hangar via taxiways E and P that I was able to see the faded white line that designates the border of Ramp C and realized that I may have made an incursion onto taxiway P at the beginning of the flight. The next day I sought out a highly experienced instructor who has operated out of DWH for over forty years and asked him about Ramp C; the faded white line; and the boundary between Ramp C and Taxiway P. He informed me that the area is tighter than I realized; and that anything west of the white line is a movement area requiring a clearance. Most importantly; I should not have assumed; and simply called Ground and coordinated with them; that way there would not have been an issue. Additionally DWH has a reputation for being poorly marked and I should have sought out more help becoming familiar with an airport that is new to me. My perception based on looking at the airport diagram was erroneous; and it was poor judgment to not call Ground and simply get cleared into the movement area; instead of trying to squeeze along the edge inside of Ramp C. I'm comfortable talking to controllers; I thought I could safely and legally do it and didn't want to 'bother them'. The reality is that's what they are there for; and I am sure the controllers would have preferred a call if there was any doubt.  The biggest factor affecting performance was the difficulty to see the faded border line of Ramp C. Additional factors were a reluctance to bother ATC; and the movement of road vehicles all around that gave a false perception that the non-movement area was larger than it really is. Unfamiliarity with the airport; especially when operating out of the north end was also a factor. The major inaction was failing to contact ATC.




Synopsis: A pilot reported they failed to contact ATC for taxi instructions. The pilot reported that while avoiding congestion on the ramp they had a taxiway incursion.