Download, print and study this document offline |
Page 1 Introduction to intersection control (Objectives) Understand why some sort of control is essential to allocate ROW at intersections Understand there is hierarchy of intersection control (Traffic signal is NOT a cure-all) Learn how to check sight distances available at an intersection Learn about the warrants for stop and yield controls Learn how to check traffic signal warrants (No need to read pages 389-392 because it will not be in the 2000 MUTCD.) Page 2 Introduction to intersection control (Objectives) Understand why some sort of control is essential to allocate ROW at intersections Understand there is hierarchy of intersection control (Traffic signal is NOT a cure-all) Learn how to check sight distances available at an intersection Learn about the warrants for stop and yield controls Learn how to check traffic signal warrants (No need to read pages 389-392 because it will not be in the 2000 MUTCD.) Conflict points at unsignalized intersections T intersection Crossing = 3 Merging = 3 Diverging = 3 Total = 9 4-leg intersection Total = 32 Page 3 Introduction to intersection control (Objectives) Understand why some sort of control is essential to allocate ROW at intersections Understand there is hierarchy of intersection control (Traffic signal is NOT a cure-all) Learn how to check sight distances available at an intersection Learn about the warrants for stop and yield controls Learn how to check traffic signal warrants (No need to read pages 389-392 because it will not be in the 2000 MUTCD.) Conflict points at unsignalized intersections T intersection Crossing = 3 Merging = 3 Diverging = 3 Total = 9 4-leg intersection Total = 32 Hierarchy of intersection control Intersection Control Options: How much judgment can drivers safely exercise to avoid collisions? Three levels of control are available. Level I Passive control – basic rules of the road apply Ø No control Ø Guide signs only Ø Warning sings with or without guide signs Level II Assignment of ROW to major street or rotational ROW Ø YIELD control (roundabouts are in this category) Ø Two-way STOP control Ø All-way STOP control Level III Positive alternate assignment of exclusive ROW Ø Traffic signals: 2-phase, multiphase Ø Traffic control agent/officer Page 4 Introduction to intersection control (Objectives) Understand why some sort of control is essential to allocate ROW at intersections Understand there is hierarchy of intersection control (Traffic signal is NOT a cure-all) Learn how to check sight distances available at an intersection Learn about the warrants for stop and yield controls Learn how to check traffic signal warrants (No need to read pages 389-392 because it will not be in the 2000 MUTCD.) Conflict points at unsignalized intersections T intersection Crossing = 3 Merging = 3 Diverging = 3 Total = 9 4-leg intersection Total = 32 Hierarchy of intersection control Intersection Control Options: How much judgment can drivers safely exercise to avoid collisions? Three levels of control are available. Level I Passive control – basic rules of the road apply Ø No control Ø Guide signs only Ø Warning sings with or without guide signs Level II Assignment of ROW to major street or rotational ROW Ø YIELD control (roundabouts are in this category) Ø Two-way STOP control Ø All-way STOP control Level III Positive alternate assignment of exclusive ROW Ø Traffic signals: 2-phase, multiphase Ø Traffic control agent/officer Assessing the viability of basic rules- of-the-road Primary prerequisite for safety under basic rules-of-the-road: Sight distance must be adequate for the driver before he is accountable for full responsibility for his action. è The first thing you want to check is whether adequate SSD is available at the intersection. This must be satisfied before traffic volume concerns come into consideration. a b d a d b A B - = - From the similarity of triangles: b d ad d A A B - = Page 5 Introduction to intersection control (Objectives) Understand why some sort of control is essential to allocate ROW at intersections Understand there is hierarchy of intersection control (Traffic signal is NOT a cure-all) Learn how to check sight distances available at an intersection Learn about the warrants for stop and yield controls Learn how to check traffic signal warrants (No need to read pages 389-392 because it will not be in the 2000 MUTCD.) Conflict points at unsignalized intersections T intersection Crossing = 3 Merging = 3 Diverging = 3 Total = 9 4-leg intersection Total = 32 Hierarchy of intersection control Intersection Control Options: How much judgment can drivers safely exercise to avoid collisions? Three levels of control are available. Level I Passive control – basic rules of the road apply Ø No control Ø Guide signs only Ø Warning sings with or without guide signs Level II Assignment of ROW to major street or rotational ROW Ø YIELD control (roundabouts are in this category) Ø Two-way STOP control Ø All-way STOP control Level III Positive alternate assignment of exclusive ROW Ø Traffic signals: 2-phase, multiphase Ø Traffic control agent/officer Assessing the viability of basic rules- of-the-road Primary prerequisite for safety under basic rules-of-the-road: Sight distance must be adequate for the driver before he is accountable for full responsibility for his action. è The first thing you want to check is whether adequate SSD is available at the intersection. This must be satisfied before traffic volume concerns come into consideration. a b d a d b A B - = - From the similarity of triangles: b d ad d A A B - = Rule 1: Both vehicles have at least one safe SSD to the collision point Step 1: Assume that Vehicle A is located one safe SSD from the collision point. Step 2: Based on the assumed position, determine the location of Vehicle B when it first becomes visible. Call it d B(act) Step 3: Rule 1 requires Vehicle B to have one safe SSD. Call it d B(min) . Step 4: If d B(act) / d B(min) , then adequate SSD for basic rules-of-the-rule has been provided. Otherwise, violated and under Rule 1, not safe. ( ) G f S t S d A A A ± + = 30 468 . 1 2 b d ad d A A B - = ( ) G f S t S d B B B ± + = 30 468 . 1 2 (min)Read More
22 videos|68 docs|39 tests
|