Former materials engineer John Parkinson, 76, from Northallerton was discovered by Traffic Officers on the Leeming to Barton site taking pictures earlier this month.
After delving further into why he was on the site, officers discovered that Mr Parkinson was part of the original team which built that section of the A1 in 1963.
After taking him safely off the A1 the officers took his details and asked him if he would like the opportunity to visit the scheme a major project by Highways England to upgrade the A1 to motorway standard between Leeming and Barton
Mr Parkinson, who describes himself as one of the last remnants of the old brigade of road construction in England, was thrilled to be invited back to take a closer look.
He has maintained a keen interest in road construction and has a huge archive of pictures recording the first days of the motorway in the North East.
Mr Parkinson recalls:
The opening of the first Darlington Bypass was quite an event and everyones family came to the opening, with women and children mixing in with the crowds.
There have been many changes in road construction in the past 50 years and major improvements in health and safety.
Swapping engineering challenges with current project manager Tom Howard, Mr Parkinson commented on the differences between road construction in the 60s and now.
Mr Parkinson said:
There is much more consideration of the public these days than during my time on the roads. Of course back then there was a huge enthusiasm for roads it was a different atmosphere and time altogether much easier. If we wanted to go through someones vegetable plot we were told we could!
In those days we used to work at night wearing black donkey jackets moving around alongside huge earth moving machines - inconceivable now of course but it did mean that you developed eyes in the back of your head.
It is wonderful to see how things are shaping up and to observe the modern approaches to project management. The most important thing now, as it was then, is to finish a job that lasts and will be part of a legacy, changing the landscape for the better.
Highways England project manager, Tom Howard, said:
I really enjoyed the opportunity to speak to Mr Parkinson and hear about his experiences as an engineer in the 60s.
It was wonderful to be able to invite him onto the site and show him the technology now in place for major schemes such as this and discuss the differences in engineering challenges between then and now.
Stuart Culley, Public Liaison Officer for the scheme at Carillion Morgan Sindall, said:
It was a pleasure to have Mr Parkinson on site and show him around the work we are doing to upgrade this stretch of motorway.
Once completed the A1 Leeming to Barton scheme will unlock growth and boost the economy by creating a continuous motorway-standard route between London and Newcastle (including the M1 and A1M). It will also improve journey times and increase safety.
When the scheme opens to traffic in 2017, journey times between Leeming and Barton are expected to be reduced by approximately 20 per cent, and over a sixty-year period, the improvements are predicted to save around 20 lives and prevent around 450 serious accidents.
Members of the public should contact the Highways England customer contact centre on 0300 123 5000.
Journalists should contact the Highways England press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.