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Acceleration rates for curve entries of 'typical' driver?

Posted: Tue May 08, 2012 9:56 am
by MSI
Q: Interested in acceleraton rates for vehicles while merging onto a 70 mph freeway, but the vehicle first has to negotiate an approximate 300-foot long, 250-foot radius curve on the on-ramp.
What I am looking for would be lateral acceleration values for a "typical" driver (like that guy even exists...) negotiating such a curve

A: Research we did with Jack Leisch and associates which included field observations and also utilized the HVOSM simulation program (McHenry's part of the research) includes observations and simulations of curve entries.
Most of the data is presented as 'vehicle radius' as compared to 'design radius' and tire 'friction demand'. From these you can determine the typical 'acceleration'.
The report is Safety and Operational Considerations For Design of Rural Highway Curves
Contract DOT-FH-11-9575
  • This research was performed to study the safety and operational characteristics of two-lane rural highway curves. A series of interdependent research methodologies was employed, including (1) multivariate accident analyses; (2) simulation of vehicle/driver operations using HVOSM: (3) field studies of vehicle behavior on highway curves; and (4) analytical studies of specific problems involving highway curve operations.
    Among the study findings are recommendations regarding design of the highway curves. The research indicated important trade-offs among curve radius, curve length and superelevation. The value of spiral transitions was demonstrated by the studies of driver behavior. Significant path overshoot was observed at all sites regardless of the curve radius; this behavior was also modeled by HVOSM. Studies of accidents on highway curves showed single-vehicle run-off-road accidents to be of paramount concern. Roadside treatment countermeasures were found to offer the greatest potential for mitigating the frequency and severity of accidents on rural highway curves
For additional reports from that Highway Curve contract see 'Over 40 years of McHenry Technical Reports:HVOSM'
Also see