MEASURES OF THE LATERAL PLACEMENT OF PASSENGER CARS AND OTHER VEHICLES IN PROXIMITY TO INTERCITY BUSES ON 2 LANE AND MULTILANE HIGHWAYS

LATERAL PLACEMENT MEASURES ON THE HIGHWAY ARE PRESENTED FOR MC-6 AND MC-7 INTERCITY BUSES, AND FOR ADJACENT VEHICLES OVERTAKING AND PASSING THE BUS. THE TEST CONDITIONS WERE MAINLY 2 LANE AND MULTILANE HIGHWAYS IN RURAL FLAT TERRAIN. SOME MEASUREMENTS INVOLVED UPGRADE AND URBAN CONDITIONS. BOTH NO-WIND AND CROSSWIND CONDITIONS WERE STUDIED, LANES WERE 12 AND 13 FT WIDE, AND BUS SPEED WAS TYPICALLY 50-55 MPH. THE BASIC DATA WERE OBTAINED WITH SYNCHRONIZED CAMERAS, MOUNTED INSIDE THE WINDOWS ON THE LEFT SIDE. THE DATA WERE REDUCED TO OBTAIN CAR-BUS RELATIVE SPEED, CAR SPEED, BUS TRAJECTORY IN LANE, CAR TRAJECTORY RELATIVE TO BUS, AND CAR TRAJECTORY RELATIVE TO LANE; FOR ABOUT 1100 PASSING ENCOUNTERS. THE DATA SHOWED NO DIFFERENCE IN ADJACENT VEHICLE PLACEMENT BETWEEN MC-6 AND MC-7 BUSES, FOR GIVEN CONDITIONS. IN EVERY CASE THE CORRESPONDING DIFFERENCES OF THE EFFECTS OF THESE TWO BUS TYPES WAS SMALL COMPARED TO THE OVERALL DISPERSIONS AND DATA RESOLUTION. WHEN IN THE LANE NEXT TO THE BUS ON A MULTILANE HIGHWAY, THE MEAN LATERAL PLACEMENT OF THE ADJACENT VEHICLE WAS OFFSET ABOUT 1 TO 1.5 FT TO THE LEFT OF ITS CENTERLINE REGARDLESS OF BUS TYPE. THIS SHIFT FROM THE CENTERLINE DID NOT OCCUR IN LANES FURTHER FROM THE BUS. THE CAR-BUS RELATIVE SPEED DATA SHOWED SOME SLOWING OF THE CAR ALONGSIDE THE BUS, AND THIS MAY RELATE TO THE INCREASED AERODYNAMIC DRAG FORCE WHICH RESULTS FROM THE AIR FLOWING AROUND THE BUS. /FHWA/

• Corporate Authors:

  Systems Technology, Incorporated

  13766 South Hawthorne Boulevard
  Hawthorne, CA  United States  90250

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Weir, D H
  • Sihilling, C S
• Publication Date: 1972

Media Info

• Pagination: 57 p.

Subject/Index Terms

• TRT Terms: Aerodynamics; Automobiles; Buses; Cameras; Lateral placement; Passing; Speed; Traffic lanes; Width
• Old TRIS Terms: Aerodynamic configurations
• Subject Areas: Highways; Operations and Traffic Management; Public Transportation;

Filing Info

• Accession Number: 00225033
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: Final Rpt., HS-013 556
• Contract Numbers: DOT-FH-11-7570
• Files: HSL, TRIS, USDOT
• Created Date: Jul 8 1973 12:00AM