S. The Grand Trunk Road, also known as GT Road, is one of the oldest and longest roads in South Asia. It was initially built by Emperor Sher Shah Suri in the 16th century, connecting the cities of Calcutta (now Kolkata) in West Bengal and Delhi. The road served as a major trade and transportation route during the Mughal period.

However, due to various invasions and changes in power, the road fell into disrepair over time. It was during the British colonial era that significant efforts were made to rebuild and improve the Grand Trunk Road.

In the mid-19th century, British engineer Sir Proby Cautley was appointed to oversee the reconstruction of the road. Cautley, along with his team, worked on widening and improving the road to accommodate wheeled vehicles and enhance its overall infrastructure.

The construction work on the Grand Trunk Road involved clearing the existing route, leveling the surface, and building bridges and culverts where necessary. The road was also widened to allow easier passage for carriages and carts.

The project faced several challenges, including difficult terrains, river crossings, and the need to ensure a smooth connection between various towns and cities along the route. Despite these obstacles, the work progressed steadily, and the road was completed in the 1850s.

The completion of the Grand Trunk Road had a significant impact on trade, communication, and travel in the region. It provided a vital link between Calcutta and Delhi, facilitating the movement of goods, people, and information. The road became a lifeline for various towns and cities along its course, fostering economic development and cultural exchange.

Over time, the Grand Trunk Road has undergone further improvements and expansions. Today, it stretches over 2,500 kilometers (1,500 miles) across India, Pakistan, and Bangladesh, connecting major cities and towns in the region. It remains an important transportation artery, playing a crucial role in the socio-economic fabric of South Asia.