Below highlights some of my survey experiences:

2025 Sept Phnom Penh: Lead Transport Study Unit (ITC) to conduct Traffic survey and Parknig survey for Urban transport study

2023 March- 2024 (Phnom Penh):  Transport survey for JICA Project, under" The Project for Capacity Development on Comprehensive Traffic Management Planning and Traffic Control Center Operation  and Maintenance in Phnom Penh Capital City.

The transport surveys  cover 10 intersections at several dates, include:
1) Directional Traffic Counting Survey,
2) Driver Violations Survey, 

3)  Queue Lenght Survey,

4) Travel Speed Survey, 

5) Topography and Intersection Layout Survey

Dr. Kheang lead the Transport Study Unit fo this  transport surveys and trained about 40 survey supervisors and surveyors. 

2023 April (Sihanoukville):  Survey and site visit on logistics and port operations.
-Sihanoukville Autonomous Port (PAS): Port Operation and management, Port Infrastructure development, Port planning and expansion,  Container handling, Vessel/ship services, Special economic zones, etc.
-Sihanoukville: transport infrastructure development and connectivity, logistics center,  dryport, ports, major roads for logistics activities, etc.

2022 Aug-Sept: (Phnom Penh):  Provision of survey for the JICA-LBE-ITC Research Project "How the poor commute in Phnom Penh.
-Interview survey with >500 garment workers in Phnom Penh

-Interview Survey with truck drivers, who transport garment workers
-GPS survey with vehicles, which transport garment workers

-2021 February  (Phnom Penh): [team leader, CKS] Provision of Resident survey on Citizen well-being in Phnom Penh, under SUTD project "Future Asian Cities -- Citizens Urban Science: Policy and Practice", approximately 1100 interviewed respondents.

SUTD: The Singapore University of Technology and Design.
CKS: The Center for Khmer Studies.

-2021 January (Sihanouk Ville): Site/construction investigation/survey of PNH-SHV Expressway.

-2021 January (Cambodia-Vietnam Borders): Cross-border logistics survey

-2020 August (Phnom Penh): Full traffic Survey of intersection at Kbal Thnol intersection, for Phnom Penh City Hall, to improve traffic flow at intersection.

-2020 April (Phnom Penh): Primary Survey of physical intersection at Kbal Thnol intersection, for Phnom Penh City Hall traffic assessment.

-2020 March (Phnom Penh): Traffic count survey for JICA PiBO project (Improvement of public bus service using rapid bus lane and priority signalization).

-2020 Jan (Cambodia): Survey of physical Geometry and parking behaviors for secondary streets  in Phnom Penh, for Phnom Penh City Hall One-Way traffic study.

-2019 Nov (Cambodia): Traffic Count Survey, Speed measurement, Vehicle classification and occupancy for UNDP Urban Study project. 

-2019 July & Nov (Cambodia): Traffic survey at several intersections in Phnom Penh for Phnom Penh City Hall Traffic Improvement Study. I am leading a survey team of 20 surveyors, whom i first trained them to fully understand how to collect traffic data including traffic count, vehicle classification, vehicle occupancy, vehicle speed , and intersection geometry via topo survey. 

-2018 Dec (Cambodia): A questionnaire-based interview survey was conducted with general citizens (N = 1,200) in Phnom Penh. Eleven surveyors, who were trained to fully understand and administer the questionnaire, visited several locations around Phnom Penh such as schools, markets, terminals, bus stops, and general public places. Respondents were recruited with an incentive gift. The questionnaire contains five parts. Part 1 asked citizens about their general trips. Part 2 first asked them about the RHAs in Phnom Penh. Part 3 asked them about their viewpoints on mass transit system. Part 4 asked them about a stated preference choice. And Part 5 asked about their personal information. The perception questionnaire items were based on a 5-point scale (1: very unlikely, 2: unlikely, 3: neither, 4: likely, and 5: very likely). This study mainly analyzed the data from part 1, 2, and 5.  

-2018 Dec (Cambodia): A questionnaire-based interview survey was conducted with Remork and Motodop drivers, who operated without RHAs, in Phnom Penh. The questionnaire was written in Khmer and contains four parts. Part 1 asked the drivers about their general transport services. Part 2 first asked them about the advent year of RHAs in Phnom Penh, and then asked them to report their operational services both before and after the advent of RHAs. Part 3 asked them about their perception toward RHAs. The perception questionnaire items were based on a 5-point scale (1: very unlikely, 2: unlikely, 3: neither, 4: likely, and 5: very likely). And Part 4 asked about personal information. Three surveyors, who were trained to fully understand and administer the questionnaire, visited several locations around Phnom Penh such as markets, major intersections, terminals, bus stops, hotels, and general public places along the city streets. A simple random sampling technique was adopted—the surveyors did not request every driver they saw to join the survey. Instead, for example, they requested only two or three drivers at a pick-up station. This thus allows a wider geographical sampling distribution across the city—i.e., a variety of information would be collected from drivers at several different locations in the city. With budget and time constraints, we tried to maximize our sample size during the survey period. A potential sampling bias could be that our survey locations mainly concentrated around the downtown areas, where more drivers could be spotted, while only a few drivers were recruited at suburban areas. At suburban areas, the demand for transport services via RHAs may not change much. The surveyors requested approximately 280 drivers, but only 217 respondents voluntarily participated in the survey. The drivers rejected our requests because they were busy, tired, waiting for customer, and afraid that the surveyors were possibly advertisers for a company or for a politician. Respondents were recruited with an incentive gift (i.e., a pen). On average, each respondent took 10-12 minutes to answer the questionnaire. 

-2018 Jan (Cambodia): Four surveyors were trained to fully understand and administered the questionnaire. There were no specific interview locations had been pre-defined. Paratransit drivers operated with RHAs were acquired by three different methods. First, surveyors sought for RHA drivers on city streets by a visual inspection. They approached the drivers whose vehicles were attached with RHA logos. Second, surveyors visited RHA companies. There, the drivers who already registered to RHAs came to pay for the commission fee or have their vehicles maintained. And third, surveyors made a booking via RHAs, calling drivers to a designated location. The shortest trip-distance was selected for minimum fare. Upon arrival, the drivers were queried whether they would participate in the survey. Yet, only four drivers were recruited using this method. The surveyors requested approximately 300 drivers, of which 197 voluntarily participated in the survey.

-2016 May (Cambodia): Qualitative survey with Stakeholders (government official, National road safety committee, road safety expert).

-2016 May (Cambodia): A questionnaire survey was conducted with the actual users of Motodops and Remorks (N = 1,000) in Phnom Penh. Eleven surveyors were trained to fully understand and administer the questionnaire. They visited several major destinations around Phnom Penh such as markets, major intersections, intercity bus terminals, and sightseeing places to collect the data. Simple random sampling was adopted:surveyors did not request every person they met to join the survey. They initially observed and then verbally confirmed whether a targeted person travelled by Motodop or Remork on a given day. The interviews were carried out along the streets at suitable places such as along the sidewalks, under the trees, or in front of a market.

-2014 Dec (Cambodia): Four surveyors, who were trained to fully understand and administer the questionnaire, conducted face-to-face interview surveys with appoximately 200 paratransit drivers in Phnom Penh. The questionnaire contained four sections. Section 1 asked about paratransit services in general and paratransit vehicles. Sections 2 asked about the fare levels defined by paratransit drivers for different pre-defined ODs and number of passengers. Section 3 asked about subjectives evaluation on paratransit operations. and Section 4 asked about personal information. The surveyors visited several locations including nera major road intersections, markets, and airport. Targeted respondents were drivers of Motodops and Remorks. Surveyors randomly requested drivers, who were waiting for passengers at their pick-up points. GPS for each mode was also used to obtained travel route and speed. 

-2015 Mar (Cambodia): Qualitative interview survey with stakeholder of paratransit services in Cambodia. Interviewees include heads of labor association, driver association, and owners of Remork manufacturers.

-2014 Feb (Cambodia): Eight surveyors were trainned to fully understand and adminster the survey questionnaire. The face-to-face interviews took place with N = 1,100 bus passengers on-board (547 of which were female). Collected information included personal characteristics, trip purpose, previous travel modes before public bus services were available, access/egress distance to/from a bus stop, and subjective questions. 

-2013 May-June (Phillipines): The interview survey was conducted in Manila by three experienced interviewers, who were trained to fully understand and administer the questionnaire. The interview was conducted in Tagalog so that the local residents would clearly understand the content of the questionnaire, although many of the Filipinos who were questioned could actually understand English. The interviewers were accompanied by a local coordinator, who was known to the general residents and who was appointed by the local authorities to assist in the survey activities. The interviews took place both inside and outside the dwellings, depending on security issues and privacy concerns. The survey team did not visit every house, as they were aware it was lunchtime. The team visited approximately 500 houses, and 341 responses were obtained. 

-2012 July (Japan): Two well-trained instructors conducted the headphone experiment interviews at two location: inside a Tokyo Tech Library and inside a room of 3.6 m x 6.4 m x 2.5m. The background sound level was monitored and did not exceed 40 dBA, the lowest limite of urban ambient sound in daytime hours. During interview about 60 normal-hearing respondesnts (or subjects) were instructured to properly wear the heaphone to minimize the effects of passive noise. After hearing different noise level, respondents were asked about their perception and noise tolerability level.