NTL Record

Title Alternative design consistency rating methods for two-lane rural highways
Record ID 11681
Personal Name
Creator
Anderson, Ingrid; Bauer, Karin M.; Collins, Jon M.; Fitzpatrick, Kay; Green, Paul; Harwood, Douglas W.; Koppa, Roger; Krammes, Raymond A.; Parma, Kelly D.; Poggioli, Brian; Tsimhoni, Omer; Wooldridge, Mark D.
Corporate
Contributor
Texas Transportation Institute
Publisher United States. Federal Highway Administration
Publication Date 20000800
Language English
Abstract Design consistency refers to the conformance of a highway's geometry with driver expectancy. Drivers make fewer errors in the vicinity of geometric features that conform with their expectations. Techniques to evaluate the consistency of a design documented within this report include alignment indices, speed distribution measures, and driver workload. Alignment indices are quantitative measures of the general character of a roadway segment's alignment. Potential indicators of geometric inconsistency include a large increase in the magnitude of the alignment indices for a successive roadway segment or feature or a high rate of change occurring over some length of road. Speed distribution measures--including variance, standard deviation, coefficient of variation, and coefficient of skewness--were investigated as potential candidates for a consistency rating method. The results indicated that speed variance is inappropriate as a design consistency measure for horizontal curvature. Driver workload is a measure of the information processing demands imposed by roadway geometry on a driver. The efforts for this study used both objective and subjective measures to model geometric features and combinations of features in terms of the difficulty that they pose to drivers. Vision occlusion, subjective difficulty ratings, a driving simulator, and an eye-mark system were used during the research. 67 Figures, 37 tables, 80 references. 3776k; 154p.
Rosap ID dot:14744
Rosap URL https://rosap.ntl.bts.gov/view/dot/14744
TRT Terms Highway design; Geometric design; Computer models; Design speed; Speed distribution; Computer aided design; Rural highways; Two lane highways; Speed limits; Highway planning; Highway safety; Research; Visual perception
General Subjects Design consistency, Alignment indices; Driver workload; Highway geometric design consistency evaluation methods; Interactive Highway Safety Design Model (IHSDM); Speed profile
Classification NTL - HIGHWAY/ROAD TRANSPORTATION - HIGHWAY/ROAD TRANSPORTATION;
NTL - HIGHWAY/ROAD TRANSPORTATION - Design;
NTL - SAFETY AND SECURITY - Human Factors;
NTL - SAFETY AND SECURITY - Speed Limits;
NTL - SAFETY AND SECURITY - Highway Safety
Geographical
Coverage
United States
TRIS Online
Accession No
00819633
Report Number FHWA-RD-99-172
Resource type Research Paper
URL https://ntlrepository.blob.core.windows.net/lib/11000/11600/11681/99172.pdf
Format PDF
Database NTL Digital Repository