PURPOSES: This paper proposes a reliability index for the safety evaluation of freeway sections. It establishes a reliability index as a safety surrogate on freeways considering speeds and speed dispersions.
METHODS : We collated values of design elements including radii, curve lengths, vertical slopes (absolute values), superelevations, and vertical slopes from seven freeway sections in Korea. We also collected data about driving speeds, traffic accidents, and their deviations. We established a reliability index using these variables.
RESULTS : The average radii, curve lengths, and superelevations are highly correlated with the incidence of traffic accidents. Deviations in radius and curve lengths show an especially high correlation. The reliability index, derived from speed and speed dispersions of the seven freeway sections, also correlated highly with accidents with a correlation index of 0.63.
CONCLUSIONS : Since the reliability index obtained from speed and speed dispersions are highly correlated with traffic accidents, we conclude that a reliability index can be a safety surrogate on freeways considering speeds and speed dispersions together in terms of design and operational levels.

1. 서론
  1.1. 신뢰도 이론의 정의
  1.2. 고속도로에서 이동성과 안전성의 성능
  1.3. 연구 배경 및 목적
 2. 연구문헌 고찰
 3. 자료 및 방법론 검토
  3.1. 대상지 특성의 수집
  3.2. 신뢰도 이론 적용
  3.3. 데이터의 수집 및 가공
 4. 신뢰도 지수 및 교통사고와의 연관성
  4.1. 설계요소 변수와 교통사고 건수와의 연관성
  4.2. 설계요소 변수의 표준편차와 교통사고 건수와의 연관성
  4.3. 신뢰도지수와 교통사고 건수와의 연관성
  4.4. 토론
 5. 결론
 REFERENCES

• 오흥운(경기대학교 공과대학 도시·교통공학과 교수) | Oh Heung-Un 교신저자