People walk slower while texting on their mobile phones to try to avoid accidents, according to new research.

And they often make large, exaggerated movements to negotiate crowds and compensate for their diminished vision.

One of the researchers, Dr Conrad Earnest, had the idea for the study after becoming irritated at the "drunken weaving" of pedestrians on their mobile phones in Bath city centre.

He enlisted the help of two University of Bath undergraduates, Robynne Smith and Sammy Licence, to carry out the research as part of their studies.

They took 30 people and made them complete three different walking tasks around an obstacle course.

The participants - aged between 18 and 50 - did the course while walking normally, texting and walking, and texting and walking while being cognitively distracted with a simple maths test.

The researchers examined the walkers' gait using a 3D motion analysis system and modelled each task to assess the differences between trails.

The authors found that participants took significantly longer to complete the course while texting and being cognitively distracted compared to just walking.

Texting while being cognitively distracted also increased obstacle clearance, step frequency and decreased someone's ability to walk in a straight line.

The authors of the study suggest participants - when faced with cognitive challenges - decrease their walking speed to avoid accidents.

They found that texting causes people to slow their pace and make large, exaggerated movements to negotiate crowds and compensate for their diminished vision.

Dr Earnest said: "One day I was walking on the high street and totally frustrated by the 'drunken weaving' about of texters who were also trying to carry on phone conversations during their shopping.

"Deciding to seek refuge, I went into a local coffee shop and was equally annoyed by people in queue placing their orders, texting and or talking on their phones.

"The idea was secured after watching a YouTube video and reading an article on inattentional blindness where people did not notice a unicycling clown while using their mobile phones.

"People slowed their walking speed, took more steps in their approach to common obstacles, and increased the height of their step to go up steps and over curbs."