Commonwealth of Massachusetts
Direct Vision Study
Current Fleet Analysis and Potential Safety Criteria
Alyssa Brodeur, Juwon Drake, Eric Englin, Alexander K Epstein, PhD, Hannah Pannell,
and Sarah Yahoodik, PhD
Photo credit: Volpe
July 2024
DOT-VNTSC-MADOT-24-01
Prepared for:
Massachusetts Department of Transportation
Notice
This document is disseminated in the interest of information exchange. The United States
Government assumes no liability for the contents or use thereof.
These recommendations represent the best technical judgement of U.S. DOT Volpe Center
staff based on their independent and objective technical analysis and expertise and are not
to be misconstrued as statements of U.S. DOT policy, MassDOT policy, or guidance.
Reference to any specific company, products, processes, or services by trade name,
trademark, manufacturer, or otherwise in the report does not constitute or imply its
endorsement or recommendation by the Volpe Center.
Acknowledgments
The authors wish to thank the Massachusetts Department of Transportation (MassDOT) for
sponsorship of this work, for arranging access to fleet vehicles, and for collaboration in data
collection and processing, with special thanks to the Lab @ MassDOT including Kris Carter,
Jaclyn Youngblood, Grace Coffelt, Hadar Sachs, and Julia Camacho. Thank you to the MassDOT
operations team that made vehicles available to study, including Scott Wilson, Robert Buckley,
and Joe Suppa. Thank you to the ten municipal partners, Cambridge, Everett, Gardner,
Falmouth, Lynn, Medford, Needham, Somerville, Waltham, and Westfield who raised their hand
to have their fleets be part of this study. The authors appreciate the partnership of Becky
Mueller and her team at the Insurance Institute for Highway Safety in developing and sharing
the open-source blind zone assessment software used in this study. The team also thanks Lou
Whiting for graphic design support, Ruth Esteban-Muir (NHTSA) for draft review, and staff at the
ten municipalities that participated and made their fleet vehicles available to the study.
 Contents
Contents................................................................................................................................ v
List of Tables .......................................................................................................................... v
List of Figures ....................................................................................................................... vi
1 Introduction and Context .............................................................................................. 10
1.1 What is direct vision?................................................................................................................. 10
1.2 Existing direct vision standards, regulations, or programs ....................................................... 11
1.3 Project context........................................................................................................................... 15
2 MassDOT and Municipal Fleet Analysis ......................................................................... 18
2.1 Fleets overview and vehicle selection ....................................................................................... 18
2.2 Methods ..................................................................................................................................... 19
2.2.1 Data collection .............................................................................................................. 20
2.2.2 Data processing ............................................................................................................ 20
2.2.3 Data representation ..................................................................................................... 22
2.3 Results ........................................................................................................................................ 25
3 Applying the Study........................................................................................................ 31
3.1 Minimum direct vision criteria .................................................................................................. 31
3.2 Countermeasures for low-vision trucks..................................................................................... 37
3.3 Future exploration: area-based and volume-based methods of evaluating direct vision ........ 40
3.4 Incorporating direct vision in procurement .............................................................................. 44
3.4.1 Document and Language Options ................................................................................ 44
3.4.2 Proposed Reporting Method ........................................................................................ 45
3.5 Future work................................................................................................................................ 47
4 Appendix ...................................................................................................................... 53
4.1 Data collection SOP.................................................................................................................... 53
4.2 Data processing details .............................................................................................................. 58
4.3 An Act to Reduce Traffic Fatalities ............................................................................................. 62
List of Tables
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Table 1. Total vehicles measured by Fleet. .................................................................................................19
Table 2. Vulnerable road user dimensions based on anthropometric sources ..........................................24
Table 3. Distances to vulnerable road users forward and on passenger side of driver, aggregated by
vehicle weight category. .................................................................................................................30
Table 4. Proposed direct vision rating system based on standard crosswalks and buffered bike lanes ....32
List of Figures
Figure 1: View from the driver's seat of an International HV 513. Direct vision of the environment is
shaded green (unobstructed view through the windows), indirect vision areas are shaded purple
(mirrors and camera display unit), and the blind zone areas are shaded in orange (hood, A and B
pillars, and door). ............................................................................................................................10
Figure 2. Illustration of different truck cab designs. ...................................................................................11
Figure 3. Direct Vision Standard operator guidance. ..................................................................................13
Figure 4. TfL Direct Vision Standard guidance showing driver-side, passenger-side, and forward visibility
for a 1-star, 3-star, and 5-star rated vehicle...................................................................................13
Figure 5. UN Regulation 167: visible line length to each side representing the intersection of the
sightlines assessment area. ............................................................................................................14
Figure 6. Visuals from the TSR Direct Vision Measurement Kit, including the diagram for “Step 3:
Recording Measurements” (left) and the diagram for the “Direct Vision Scoring Methodology”
(right). .............................................................................................................................................15
Figure 7. MassDOT and Volpe team collecting data using standardized eye point rig and camera. ..........20
Figure 8. Example shapefile of postprocess NVP point cloud output from OGRE. .....................................21
Figure 9. Manual passenger side NVP determination (grid and y-axis label are in meters) .......................22
Figure 10. Distance-based blind zone representation of trucks by TfL for adult VRUs (top) and cyclist
VRUs (bottom). Y-axis units are millimeters. .................................................................................23
Figure 11. Forward distance (in feet) at which adults and elementary school children are first visible to
drivers in measured heavy-duty vehicles. ......................................................................................26
Figure 12. Forward distance (in feet) at which adults and elementary school children are first visible to
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 drivers in measured medium-duty vehicles. ..................................................................................27
Figure 13. Forward distance (in feet) at which adults and elementary school children are first visible to
drivers in measured light-duty vehicles. ........................................................................................28
Figure 14. Passenger-side distance (in feet) at which adults and elementary school children are first
visible to drivers in measured heavy-duty vehicles........................................................................28
Figure 15. Passenger-side distance (in feet) at which adults and elementary school children are first
visible to drivers in measured medium-duty vehicles. ...................................................................29
Figure 16. Passenger-side distance (in feet) at which adults and elementary school children are first
visible to drivers in measured light-duty vehicles. .........................................................................29
Figure 17. Nearest point at which an adult and child are visible to a driver at a standard crosswalk and
stop bar overlaid with a five-star rating system for measured heavy-duty vehicles. ....................33
Figure 18. Nearest point at which an adult and child are visible to a driver at a standard crosswalk and
stop bar overlaid with a five-star rating system for measured medium-duty vehicles. ................34
Figure 19. Nearest point at which an adult and child are visible to a driver at a standard crosswalk and
stop bar overlaid with a five-star rating system for measured light-duty vehicles. ......................35
Figure 20. Nearest point at which an adult and child are visible to a driver at a buffered bike lane
overlaid with a five-star rating system for measured heavy-duty vehicles. ..................................35
Figure 21. Nearest point at which an adult and child are visible to a driver at a buffered bike lane
overlaid with a five-star rating system for measured medium-duty vehicles (top) and light-duty
vehicles (bottom). ...........................................................................................................................36
Figure 22. Overview of countermeasures from Transport for London Direct Vision Standard (for more
details and specifications, see: https://content.tfl.gov.uk/hgv-safety-permit-guidance-for-
operators-entering-london.pdf) .....................................................................................................37
Figure 23. Diagram of BSIS’s VRU detectable range (for more details and specifications. .........................38
Figure 24. Diagram of MOIS’s VRU detectable range (for more details and specifications........................39
Figure 25. Pre-collision speeds and stopping distances, highlighting low-speed crash regime relevant to
blind zone crashes between VRUs and large vehicles; Montreal approach to assess blind zone
and visible area within 10 meters. .................................................................................................40
Figure 26. Blind zone comparison at ground of high vision and low vision Class 8 trucks (top: 2024 Dennis
Eagle Proview; bottom: 2014 International Workstar 7600). Dennis Eagle Proview has 165
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 square meters of blind zone area at the ground level within a 20 meter radius; International
Workstar 7600 has 285 square meters of blind zone area at the ground level. ............................41
Figure 27. Blind zone area (square meters) at child shoulder height within a 10-meter radius of driver. .42
Figure 28.Blind zone area (square meters) at adult shoulder height within a 10-meter radius of driver. .43
Figure 29. Percentage of ground visible within a 10-meter radius of the driver. .......................................43
Figure 30. Proposed near-term cone method of direct vision reporting for bidders. ................................46
Figure 31. Setup for 3-foot and 4-foot cone method of blind zone measurement. ...................................46
Figure 32. Illustrations of different geometric designs at intersections and crosswalks: a) protected
intersection, b) raised crosswalk, c) near-side traffic signals, and d) advance stop line. ..............48
Figure 33. MassDOT Trucking Network, with layers shown for truck exclusions. ......................................49
Figure 34. MassDOT Potential for walkable trips on MassDOT roads (2022 update). ................................49
Figure 35. MassDOT potential for everyday walking on MassDOT roads. ..................................................50
Figure 36. Potential for Everyday Bicycling map on MassDOT and all roads (top: Eastern MA; bottom:
zoom in around Cambridge-area)...................................................................................................50
Figure 37. Example of swept path visibility safety analysis for a design vehicle through an intersection
that could use data from studies such as this one to model blind zone risk to people outside of
vehicles and inform geometric, engineering, or operation countermeasures. (Courtesy:
AutoTURN / Transoft Solutions) .....................................................................................................51
Figure 38. Steering column placement for data collection. ........................................................................53
Figure 39. Seat adjustment control buttons. ...............................................................................................54
Figure 40. Laser being used to identify the exact mid-point for seat, which will be used for rig placement
and data collection. ........................................................................................................................54
Figure 41. Rig placed in driver seat. .............................................................................................................55
Figure 42. Rig with placement directions for seatback arrangement. ........................................................55
Figure 43. Close-up of rig with phone installed for measurement. ............................................................56
Figure 44. Overhead view showing the different distance calculations recorded during data collection
process. ...........................................................................................................................................56
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Figure 45. Image showing how to prepare vehicle for data collection process. .........................................57
Figure 46. Example image at 0 degrees forward from driver eyepoint. .....................................................57
Figure 47. Rig shown at close range to show the method to rotate and line up the phone into the rig. ..58
Figure 48. Aggregated images of the forward field of view for one vehicle. ..............................................58
Figure 49. Image at 0 degrees where the right side of driver A pillar to midway across front hood is
annotated. ......................................................................................................................................59
Figure 50. Image at -30 degrees where the left side of driver a pillar plus mirror is annotated. ...............59
Figure 51. Image at -60 degrees where the annotation finishes the rest of driver window. Note that this
may need to go to -90 or -120 degrees for some vehicles. ............................................................60
Figure 52. Image at 30 degrees where the annotation finishes the driver hood with some overlap and
left side of passenger A pillar. ........................................................................................................60
Figure 53. Image at 60 degrees where the entire passenger window is annotated. ..................................61
Figure 54. Raw output of nearest visible points on the ground around the vehicle. These are further
processed to remove duplicate data points and aggregate into a single polygon shapefile of the
vehicle blind zone. ..........................................................................................................................61
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1 Introduction and Context
1.1 What is direct vision?
Direct vision is the ability of a driver to see firsthand outside their vehicle without the aid of an indirect
vision device, such as mirrors or camera displays. In contrast, indirect vision is the ability of a driver to
see outside their vehicle through mirrors or camera displays. Direct vision enables eye contact between
a driver and a vulnerable road user (VRU) near the vehicle; indirect vision generally does not.
Figure 1: View from the driver's seat of an International HV 513. Direct vision of the environment is shaded green
(unobstructed view through the windows), indirect vision areas are shaded purple (mirrors and camera display unit), and the