Definition: Given a passage and a question, find the answer to the question based on the passage. The answer should consist of only one word that lies in the span of only one of the sentences in the passage.
Input: Paragraph: 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 They were first introduced in the UK by section 51 of the Road Traffic Act 1960 ( repealed in 1972 and replaced by later legislation ) .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: when were yellow lines introduced in the uk

Output:
1960