Passage: Double yellow lines mean no waiting at any time, unless there are signs that specifically indicate seasonal restrictions. They were first introduced in the UK by section 51 of the Road Traffic Act 1960 (repealed in 1972 and replaced by later legislation).

Question: Based on this passage, when were yellow lines introduced in the uk?
Steam of consciousness below:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
The relevant information is: They were first introduced in the UK by section 51 of the Road Traffic Act 1960 (repealed in 1972 and replaced by later legislation).
So, the answer is 1960.