Transportation Engineering (General Engineering) (SSC JE)

Nagpur Road Plan (1943-63) [I 20 year road development plan)
• Target - 16 km road/100 sq. km area of country
• Achieved target 2 years ahead in 1961
• This plan assumed "star and grid pattern"
• According to Nagpur Road Plan, all roads are divided into five categories– 1. National highways (NH)
2. State highways (SH)
3. Major District Roads (MDR)
4. Other District Roads (ODR)
5. Village Roads (VR)

Various gauges on world railways and Indian railways

Length or rails–Theoretically, the longer the rail, the lesser the number of joints and fittings required and the lesser the cost of construction and maintenance. Longer rails are economical and provide smooth and comfortable rides.
The length of a rail is restricted ducts following factors–
• Lack of facilities for transport of longer rails, particularly on curves.
• Difficulties in manufacturing very long rails.
• Difficulties in acquiring bigger expansion joints for long rails.
• Heavy internal thermal stresses in long rails.

Based on the location and function, the roads in India are classified into 5 categories –
(i) National highway
(ii) State Highway
(iii) Major district road
(iv) Other district road
(v) Village road)

(1) Nagpur road plan (First twenty year road plan 1943-1963)
→ 16 km/100 km²
(2) Bombay road plan (Second twenty year road plan - 1961-1981)
→ 32 km/100 km²
(3) Lucknow road plan (Third twenty year road plan - 1981-2001)
→ 82 km/100 km²

Titling of rails–Placing the rain of the track at an inward slope of 1 in 20 is known as tilting of the rails.
• The main purpose of this instrument is to reduce the wear on the inside edges of the rail in track.

For calculation of minimum stoppage distance in a sag curve, value of head light height = 0.75 m and beam angles is taken as 1ᵒ.

Kerb indicates the boundary between the pavement and medium or foot path or island or shoulder. It is desirable to provide kerbs on urban roads. Kerbs may be mainly divided into three groups based on their functions–
1. Low kerb or mountable type kerb
2. Semi barrier type kerb
3. Barrier type kerb

Width of medians–
• To avoid glare, we need 8-14 m wide medians.
• For rural highways 5 m and 3 m (if land is restricted)
• For urban area,
→ Absolute minimum - 1.2 m
→ Desirable minimum - 5.0 m
• For expressways,
→ Without median barrier : 15 m
→ With median barrier : 4.5 m