>>1819629>“Bicycles do not reduce passenger car speeds by more than 1 mph,” add the study authors concluding that cyclists are not guilty of “negatively affecting travel speed or creating congestion.”The Portland study was published June 12 in the Transportation Research Record, the journal of the National Academy of Sciences’ Transportation Research Board.
The study evaluated speeds on six roads in Portland, with on-road measurement data provided by the city’s Bureau of Transportation. Data captured by pneumatic tubes embedded on roads were collected from different times of day, including in peak traffic hours.
“A general concern of motorists [concerning] the presence of bicycles on roads without bicycle lanes is that they will impede motor vehicles because of their differing performance characteristics, which may serve to increase congestion and vehicle emissions,” explained the study, finding that a 1 mph differential in speed caused by the presence of cyclist would not cause congestion.
The study “seems quite thorough,” British academic Ian Walker told me
“It’s nice to have hard data to suggest that sharing roads with cyclists doesn’t slow down drivers by any real degree,” added Dr. Walker, a University of Bath environmental psychologist.
“A lot of sentiment towards cyclists is founded on prejudice rather than rational analysis,” he believes.
