Medians kerbs and median gaps

Highway and Pavement engineering, Highway pavement surface elements.

1. Medians and Median Barriers Functions- Separates the opposite stream of traffic. Reserves the space for future development. Reduces headlight glare by accommodating vegetation. Improves aesthetic appearance General Requirements- Median barriers are required if median width is less than 5 m. Minimum width is limited to 1.5 m.

2. Problems Associated- Traffic restriction if broken, causes congestion as well. Pedestrian accidents if uncrossable barriers are provided. Broken medians act as median openings. increasing the chance of collision. Improvements- Proper maintenance of ends and broken medians. Material used for barriers should be impact absorbing. Clear visibility must be provided at median openings.

3. Kerb s Functions- Facilitates drainage. Lateral support to the pavement. Discourages the drivers to drive on sidewalks and footpaths. Improves aesthetic appearance. General Requirements- Reveal portion varies from 10cm to 20 cm. Decided from topography present at the road site.

4. Problems Associated- If breaks, it becomes starting point for pavement deterioration. Material cost, problem can not be solved. B lockage of drainage hole. Improvements - Proper maintenance. Adequate support to the kerbs. Proper cleaning of drainage holes.

5. Median Gaps Functions - Provides refuge area for pedestrians. Provides opening to change the lane for vehicles. General Requirements Opening must be there at an interval of 1.5 km (NH) and 2.0 km (Expressways) in order to separate the damaged vehicles from carriageway. Opening width should be limited to 18 to 20 m . Projected median portion at opening should be curved.

6. Problems Associated- Chances of collision of vehicles on the opening. Pedestrian accidents may occur. Congestion due to domination of local traffic. Improvements- Limit the number of openings. Proper designing of opening- Bullet nosed shape for Right turning traffic, Semi-circular shape for U-turning traffic. Maintenance of broken corners and projected part. Restriction to local traffic.