--- title: "One-way traffic advantages and conflict points" subject: "Transportation Engineering II" chapter: 1 key: "semester_7/transportation_engineering_ii:one-way-traffic-conflict-points" source: https://www.bctengineer.com/q/semester_7/transportation_engineering_ii/one-way-traffic-conflict-points site: BCT Engineering --- # One-way traffic advantages and conflict points Transportation Engineering II · Chapter 1: Traffic Engineering - Asked in: 2081 Baisakh, 8 marks - Video: [Conflict Points at Intersection | Highway Engineering | Civil | GATE | ESE I SSC -JE](https://www.youtube.com/watch?v=23rD8UU-lbM) — Crack Civil Target - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/transportation_engineering_ii/one-way-traffic-conflict-points - Whole chapter: https://www.bctengineer.com/md/semester_7/transportation_engineering_ii/chapter-1 ## Question What are the advantages of one way traffic movement? Draw a right angle four arm intersection of two roads and show various conflict points, if both roads with two way movements? Classify the type of conflicts. ## Short answer One-way streets reduce conflict points, increase capacity, simplify signal coordination. A four-arm two-way intersection has16 crossing,8 merging,8 diverging conflicts (total32). Crossing conflicts are most severe. ## Answer #### Advantages of one-way traffic - Fewer conflict points (a four-arm junction of two one-way streets has far fewer than the 32 of two-way streets), so fewer and less severe crashes. - Higher capacity (typically 20-50 percent more) as no opposing flow, no right-turn crossing and less need for signal phases. - Easier signal coordination and progressive flow; fewer signal phases. - Parking and loading can be allowed on both sides without blocking opposing flow. - Higher speed and less delay; less glare at night; fewer head-on and sideswipe crashes. - Pedestrians only look in one direction when crossing. - No central median needed; easier lane use. Limitations: longer travel distance for some trips, confusion for strangers, and need for a parallel return street. #### Conflict points at a four-arm intersection (both roads two-way) ```text N | D | M | | | | ------- X--X-X--X -------- M D X X X X D M ------- X--X-X--X -------- D M X X X X M D ------- X--X-X--X -------- | | | | M | D | S X = crossing, M = merging, D = diverging (4 diverging + 4 merging near arm ends; crossing points in the central area) ``` Each of the four approaches has through, left-turn and right-turn movements (12 movements in all). | Type | Number | |---|---| | Crossing conflicts | 16 | | Merging conflicts | 8 | | Diverging conflicts | 8 | | **Total** | **32** | #### Classification of conflicts 1. **Diverging:** one stream splits into two (a vehicle leaves the approach stream to turn). Least severe; 2 per approach = 8. 2. **Merging:** two streams join into one at an exit. Moderately severe; 2 per exit = 8. 3. **Crossing:** two streams cut across each other's path (right turners across opposing through traffic, and cross-road through/turning movements). Most severe and most numerous = 16. Hence crossing conflicts (half of all) are the main target for control by signals, islands, rotary or grade separation. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Why does one-way traffic have higher capacity? A. Roads are wider B. No opposing flow or right-turn crossing, and fewer signal phases C. More parking is banned D. Speeds are limited Answer: B. Removing opposing flow and right-turn crossing allows 20-50 percent more capacity. (Key point: Advantages of one-way) 2. How many conflict points are at a four-arm intersection with both roads two-way? A. 16 B. 24 C. 32 D. 48 Answer: C. There are 16 crossing, 8 merging and 8 diverging, totalling 32. (Key point: Total conflict points) 3. Which correctly splits the 32 conflicts? A. 8 crossing, 12 merging, 12 diverging B. 16 crossing, 8 merging, 8 diverging C. 10 crossing, 11 merging, 11 diverging D. 16 crossing, 16 merging, 0 diverging Answer: B. Crossing is half of all conflicts; merging and diverging are 8 each. (Key point: Conflict types) 4. Which conflict type is most severe and the main target for signals, islands or rotary? A. Diverging B. Merging C. Crossing D. Parallel Answer: C. Crossing conflicts are the most severe and numerous, so controls target them. 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