The Highway Code was launched in 1931. At that time, 7,000 people were killed in road accidents each year (there were 2.3 million cars on the roads), leading to driving tests becoming compulsory on 1st June 1935 (32 years after driving licences were introduced!).
The first driving tests in 1935 cost 37.5p (compared to £62 today) and, as there were no test centres, learners had to meet the examiner at an agreed location (e.g. outside a Post Office!).
Since 1935, more than 46 million tests have been taken and, over the last 60 years, there have been several new road traffic laws and, with improved training, compulsory testing, greater public awareness, advances in technology and the introduction of British Summer Time, the number of deaths as a result of accidents on the road each year has now been halved (even though there are more than 27 million vehicles on the roads!).
While some things have not changed during that time (the first edition of The Highway Code urged all road users to be careful and considerate towards others, putting safety first), other aspects of the Highway Code have changed dramatically e.g. in 1931 mirrors were not even mentioned (I remember my first car, in 1981, didn’t even have a left door/wing mirror) and drivers were advised to sound their horn when overtaking!