Cover Image

Not for Sale



View/Hide Left Panel
Click for next page ( 39


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 38
38 Video simulation, however, potentially provides some Because the video simulation and its fidelity to a real-time significant advantages to real-time field surveys, particu- event was an important consideration and because the larly if the "moving camera" approach is used. The moving NCHRP Project 3-70 team was able to take advantage of the camera perspective gives the video simulation a greater re- FDOT study, the real-time event and coincident video simu- flection of reality as opposed to the stationary camera. lation are described below. Moving camera simulation also allows for a wider range of Staff from Dowling & Associates and Sprinkle Consulting, geographic participants and the testing of a greater range Inc., initially developed a matrix with 30 specific combina- of variables, particularly the potentially hazardous higher tions ("runs") of geometric and operational criteria. The truck volumes and the high frequencies of driveway/curb matrix is provided as Exhibit 38. cut common in jurisdictions with minimal roadway access The research team used the matrix as a guide to identify management practices. Finally, moving camera (video) filming candidate locations in Tampa. Dr. Huang and simulation, if done based on lessons learned through pre- Mr. Petritsch field-checked the locations to verify their geo- vious bicycle research, can approximate real-time condi- metric and operational characteristics. Some runs identified tions without the real-life hazards to participants in field when filling out the matrix involved unlikely combinations studies. (for example, Run #11, which specified traffic volume in out- The research team chose to use a video simulation method- side lane > 800 vph and speed limit < 30 mph). ology for this effort. The bicycle LOS research methodology Consequently, some of the combinations of variable ranges used was designed to achieve the following objectives: were not taped for the NCHRP project 3-70 study. After discussions with Mr. Reinke, the research team selected Obtain bicyclists' perceptions of the level of accommoda- alternative locations so that there would be locations for each tion provided by arterial roadways using a real-time field- value of each criterion. For example, traffic volumes of < 400, data collection event; 400-800, and 800+ vph were all represented. Coincident with the field data collection event, use video Theo Petritsch of Sprinkle Consulting, Inc. and Mr. simulations to obtain bicyclists' perceptions of the level of Michael Munroe (a professional videographer) videotaped accommodation provided by arterial roadways; the bicycle locations during March and April 2006. The video Develop an equation to correlate the video simulation platform used was a Viewpoint bicycle with Glidecam, as responses to the real-time event responses; and described above and shown in Exhibit 39. Provide the information necessary to develop the research All traffic laws were obeyed during the filming of the bicy- team's initially proposed model form. cle clips. To ensure a consistent recording methodology, and one which reflects typical bicyclists' scanning behavior, a pro- For this NCHRP Project 3-70, a video simulation was tocol was developed, tested, and used by the researchers and used to collect data for the bicycle LOS model development. videographer for proper camera panning techniques and to However, the research team took advantage of a coincident keep the roadway ahead in the right-center of the frame to bicycle facility LOS project being conducted by FDOT's focus on the roadway and capture driveway conditions while Central Office and District 7 which combined approach of not focusing on objects outside the right of way. field based studies with video simulation. This timely FDOT One or two "takes" were filmed at each location. The study involved a real-time event in which bicyclists rode a researchers started about one city block upstream of the in- study course and evaluated facilities along the course. tersection, taped while riding at approximately 12 mph, and As part of this project, we filmed moving camera videos of finished about one city block downstream of the intersection. the event route under similar conditions expected for the The team also used several video clips from those filmed for actual event. The videos were edited into digital sequence the video simulation portion of the Ride for Science 2005. videos for the creation of simulation videos for video-to- Those were filmed using the same procedures. field calibration. With guidance from Mr. Petritsch, Dr. Huang selected Following the FDOT project, NCHRP Project 3-70 pro- 30 bicycle clips for inclusion in the bicycle DVD. The geomet- duced additional video for testing in a separate video simula- ric and operational characteristics of the locations depicted in tion laboratory effort to obtain responses from additional these clips are shown in Exhibit 40. users. To ensure the consistency of the NCHRP research video survey results, the original Ride for Science (described Pedestrian Video Clips below) video clips were re-edited to match the format of those produced specifically for NCHRP 3-70. The NCHRP Pedestrians are among the most vulnerable of travellers 3-70 laboratory simulation clips were shown at four locations and are affected by a broader variety of traffic and roadway across the United States. environmental factors (stimuli) than that of the motorized

OCR for page 38
39 Exhibit 38. Bicycle Video Clip Sampling Plan. Segment variables Intersection variables Width of Presence / Veh flow in Speed Crossing Control Run outside lane width of bike outside lane (vph) limit width (ft) delay (s) (ft) lane (ft) (mph) 1 < 12 No bike lane 400 - 800 30 - 40 36 - 60 No stop 2 < 12 No bike lane 800+ < 30 60+ No stop 3 < 12 No bike lane < 400 30 - 40 < 36 < 40 4 < 12 No bike lane 400 - 800 < 30 36 - 60 < 40 5 < 12 No bike lane 800+ 40+ 60+ < 40 6 < 12 4 < 400 < 30 36 - 60 40+ 7 < 12 4 400 - 800 30 - 40 60+ 40+ 8 < 12 4 800+ 40+ < 36 40+ 9 < 12 4 < 400 40+ 36 - 60 No stop 10 < 12 4 400 - 800 30 - 40 60+ No stop 11 < 12 4 800+ < 30 < 36 No stop 12 4 < 400 30 - 40 60+ < 40 13 4 400 - 800 < 30 < 36 < 40 14 4 800+ 40+ 36 - 60 < 40 15 4 400 - 800 30 - 40 < 36 40+ 16 4 800+ 40+ 36 - 60 40+ 17 12 + No bike lane 400 - 800 30 - 40 36 - 60 No stop 18 12 + No bike lane 800+ < 30 60+ No stop 19 12 + No bike lane < 400 30 - 40 < 36 < 40 20 12 + No bike lane 400 - 800 < 30 36 - 60 < 40 21 12 + No bike lane 800+ 40+ 60+ < 40 22 12 + 4 400 - 800 30 - 40 60+ 40+ 23 12 + 4 800+ 40+ < 36 40+ 24 12 + 4 < 400 40+ 36 - 60 No stop 25 12 + 4 400 - 800 30 - 40 60+ No stop 26 12 + 4 800+ < 30 < 36 No stop 27 12 + >4 400 - 800 < 30 < 36 < 40 28 12 + >4 800+ 40+ 36 - 60 < 40 29 12 + >4 < 400 < 30 60+ 40+ 30 12 + >4 800+ 40+ 36 - 60 40+ modes. Previous research, model development, and nation- capture the participants' response to the host of stimuli pres- wide deployment of non-motorized LOS mode models have ent in urbanized roadway environments affecting pedestri- demonstrated that field-based studies are the most desirable ans. However, field studies can be expensive and, depending means to capture accurate perceptions of pedestrians. They on the range of conditions and variables being explored, rep- place the participants in typical real-life situations and resent the highest risk for participants of any method. Video simulation, however, potentially provides some sig- Exhibit 39. Bicycle Video Camera Mount. nificant advantages to real-time field surveys, particularly if the moving camera approach is used. The moving camera per- spective gives the video simulation a greater reflection of real- ity than the stationary camera. Moving camera simulation also allows for a wider range of geographic participants and the test- ing of a greater range of variables, particularly the potentially hazardous higher truck volumes and high driveway/curb cut frequencies common in jurisdictions with minimal roadway access management practices. Finally, moving camera (video) simulation, if done based on lessons learned through recent pedestrian research, can approximate real-time conditions without the real-life hazards to participants in field studies. Given these advantages of video simulation, the project team used video simulation to collect data for the pedestrian LOS model. Video clips were created and then shown to par- ticipants in video simulation laboratories.

OCR for page 38
40 Exhibit 40. Characteristics of Bicycle Video Clips. Staff from Dowling & Associates and Sprinkle Consulting, locations and Dowling & Associates staff field-checked the San Inc., initially developed a matrix (see Exhibit 41) with 22 specific Francisco locations to verify their geometric and operational combinations ("runs") of geometric and operational criteria to characteristics. Some runs involved unlikely combinations (for represent the typical ranges of urban arterials in metropolitan example, Run #11, which specified sidewalk width < 4ft and areas throughout the United States. high pedestrian volumes) and so were not included in the data The research team used the matrix as a guide to identify can- collection video simulation video. After discussions with David didate locations in Tampa and San Francisco. Herman Huang, Reinke of Dowling & Associates, the research team selected Ph.D., of Sprinkle Consulting, Inc., field-checked the Tampa alternative locations so that there would be locations for each

OCR for page 38
41 Exhibit 40. (Continued). Exhibit 41. Pedestrian Sampling Plan. Run Segment variables Intersection variables Sidewalk Separation Traffic Traffic Pedestrian Number Signal width of speed volume volumes of lanes delay (ft) walkway (mph) outside crossed (sec) from lane traffic (vph) 1 <4 No 30-40 400-800 Medium 2 < 30 2 4+ No 40+ 800+ High 2 < 30 3 No No < 30 400-800 High 2 < 30 sidewalk 4 4+ No 40+ < 400 Medium 2 < 30 5 No No < 30 800+ Medium 4+ < 30 sidewalk 6 <4 No 30-40 < 400 High 4+ < 30 7 4+ No 40+ 400-800 Low 4+ < 30 8 <4 No 40+ < 400 Medium 4+ < 30 9 4+ No <30 400-800 High 4+ < 30 10 No No 30-40 800+ Medium 4+ < 30 sidewalk 11 <4 No 40+ < 400 High 4+ < 30 12 4+ Yes 30 13 30 14 4+ Yes 30 15 30 16 4+ Yes 30-40 30 17 30 18 4+ Yes 30-40 30 19 30 20 4+ Yes 30-40 400-800 Medium 4+ > 30 21 30 22 4+ Yes 30-40 800+ Low 4+ > 30