India's overcrowded rail network

Severe overcrowding contributes to the high death tolls in Indian rail accidents

(CNN) -- India's state-owned rail system is the largest in the world, carrying some 11 million passengers every day on more than 100,000 kilometers of track.

Originally built by the British, the rail network now stretches to every major city in the country with more than 11,000 train services running daily.

Despite a massive increase in passengers and train services over the past five decades, much of the traffic management system continues to rely on equipment dating from the colonial era.

This equipment relies heavily on manual operations and many of the worst accidents in recent years have been blamed on human signaling errors.

Indian Railways itself is one of the largest employers in the country with some 1.65 million personnel.

TIMELINE • Indian rail disasters

Coupled with the severe overcrowding that is often a feature of the most popular trunk rail lines, death tolls in Indian train crashes are often very high.

Low maintenance

Bars on the windows are a common feature of Indian trains

The country's worst accident was in 1981 when a train traveling across a river in the state of Bihar was blown off its track by a cyclone.

More than 800 people died.

Deaths are often particularly high in train accidents involving rail cars falling into rivers or lakes because most Indian trains have bars welded across their windows -- a measure designed to deter theft, but which also restricts escape routes in an emergency.

A lack of investment has also resulted in low levels of track maintenance, whilst repairs to bridges and tunnels are often delayed or poorly executed due to lack of funds.

Nonetheless in terms of passenger miles and despite the high death tolls of Indian rail accidents, train travel remains statistically one of the safest means of getting around the country.

Far more people are killed on India's roads than die in rail accidents.