Cascading down the country, bound by tarmac, steel and concrete, the A1 surges with cars, lorries, vans and motorbikes for 413 unbroken miles. This torrent of traffic emerges from its northernmost point in front of Waverley railway station in the heart of Edinburgh, cuts into hillsides, laps the North Sea coast, shoots high over valleys, dodges urban sprawl, meanders through wide plains, storms across fenland and field, and eventually breaks amid the manmade canyons of London, finally fizzling out at the foot of St Paul’s Cathedral.

Hundreds of thousand of journeys a day charge along its course - an average of 91,000 motorists pass its busiest point at junction 4 in Hertfordshire every day - sometimes at breakneck speed, sometimes reduced to a trickle by roadworks, accident or congestion. Connecting north to south, and all points in between, it is one of the principal highways of our nation and arguably the largest and most enduring single object that Britons have ever created.

Flowing through at least 2,000 years of history, the detritus of Britain’s turbulent past has often been caught in its ebb and flow, scouring marks in the landscape that surrounds the route as we see it today. The road that the Romans built had no name, but its Anglo-Saxon inheritors called it Ermine Street between London and York and Dere Street beyond that. In the 18th century it became known as the Great North Road. The designation A1 was a comparatively recent innovation, the product of the 1920 Roads Act which sought a rational basis for subsidising maintenance, putting A road before B road in importance and hence funding.

All the while, its course has constantly shifted, sometimes quite radically. A curiously sited lay-by or isolated former coaching inn betrays a lost meander, an “ox-bow lake” left behind by the restless road. Whole cities, such as Lincoln and York, have found themselves abruptly abandoned as a better river crossing was built or a bypass opened.

Ultimately, each new course is forced by the changing priorities, needs and capabilities of the people whose travels define the road more than any tarmac, map or signpost ever could. The stroke of a bureaucrat’s pen might determine the precise line, but his hand is guided by necessity. Every journey along it is different in motive, situation and detail yet they all come to share a common course for at least a short time.

The early history of the road is one of conquest and subjugation. By AD80, Roman legionaries had driven a well-built highway from London to the Firth of Forth. It cut a swathe straight through newly conquered countryside and formed a key element in a network of military expressways that enabled the armies of Rome to rapidly concentrate their might to snuff out any resistance among the vanquished Britons. The route they chose bowed only to natural barriers such as hills and rivers. Tellingly, the Roman road was oblivious to age-old tribal boundaries and the sensibilities of the locals.

The straight lines of Rome cut like canals through the countryside and sent a clear message about who was in charge. The roads were highly visible bonds which tied the conquered people down. They also enabled traders to transport their wares from town to town with relative ease and, partly as a result, the Romano-British economy boomed. However, the roads soon fell into disrepair after the soldiers had gone. Some sections of the original road were completely abandoned, to be reabsorbed into the landscape. Other parts, however, remained in use, proving to be durable paths for merchants, pilgrims and other travellers, albeit often in a perilously rundown condition. The road was still a vital route for armies, a military corridor testified to by the battlefields, such as Towton and Marston Moor in Yorkshire, and fortifications, like Alnwick Castle in Northumbria, that pit the surrounding land.

Travel north to south and the journey has barely begun before we come across the site of one such famous clash of arms. Some 20 miles out of Edinburgh, just north of the A1, is the village of Athelstaneford where, in AD832, an army of Picts led by King Athelstan and Scots led by King Hungus defeated a force of Northumbrian Angles which had been pursuing it up the road. According to legend, St Andrew appeared to King Hungus on the eve of the battle. The next day, a white saltire (the diagonal cross on which the Apostle had been martyred) appeared in the blue sky to answer the Scots’

prayers for victory. Divinely woven over the old Roman road, the St Andrew’s Cross or saltire was henceforth adopted as the flag of the nation.

Continue south, down the wild North Sea coast, passing small settlements clinging to the narrow stretch of land between hill and sea, strung out along the road they now rely on for sustenance. At one point, a huge, almost featureless block rises abruptly from the shore like some modern peel tower or keep. Torness Nuclear Power Station seems rather oblivious to the road that scuttles across its shadow, its gaze directed to its own network of powerlines that send the 1,364 megawatts of electricity produced by its twin advanced gas-cooled reactors to a great swathe of Scotland.

As the border with England approaches, the A1 plunges through particularly bleak terrain, skirting the eastern flank of Halidon Hill, where a Scottish army was cut down during the English invasion of 1333. Almost immediately, we pass Berwick-upon-Tweed, a town still cocooned in the bulwarks, earthworks and stonewalls raised to prevent the Scots from recapturing it.

The town has changed hands 13 times.

The atmosphere lightens as the brooding menace of the borders gives way to the uplifting beauty of the Northumbrian coast. Enchanting views of Lindisfarne, sitting in skirts of golden sand, can tempt the traveller off course for a brief excursion across the tidal causeway. It had a similar pull on the pilgrims who for centuries walked the road to worship on the Holy Island.

At Newcastle, we cross the Tyne, four miles upstream from the centre of the only city aside from Edinburgh and London still directly connected to the road. The Romans built a bridge - the Pons Aelius - which from AD122 pretty much determined that the route had to pass through Newcastle. But in 1849, when Queen Victoria opened the iconic High Level Bridge, the road became unsettled.

In 1928, it moved downstream onto the Tyne Bridge. Then in 1967, it plunged under the river through a tunnel even further downstream at Jarrow. And 23 years later it switched again back upstream to its present crossing at Blaydon Bridge.

It was also, in part, in Newcastle that new technology was developed, which for some years seemed to pose a serious threat to the road’s future. George Stephenson’s Rocket steam locomotive was in the vanguard of the railway revolution. It may have had an inauspicious beginning - carried by road from Newcastle to Darlington in 1829 - but in the coming decades, the steel rails on which it ran would form a web over the country, ensnaring would-be road users.

For a while, the railways provided fast, safe and efficient travel when the traditional alternative was slow, unpredictable, costly and occasionally dangerous. But by the turn of the 20th century, the supremacy of the railways was being challenged once more by resurgent roads, given new purpose by the motor car.

A few miles south of Newcastle, we find ourselves becalmed, stranded amid a log jam of traffic backed up along the A1 close to Gateshead’s MetroCentre, Europe’s largest shopping mall. Our enduring reliance on cars, despite the fact that they bring more pain than pleasure, can be seen on the strained faces of every driver caught up in this congregation of retail pilgrims.

But then the Angel of the North, Anthony Gormley’s stunning 200 tonne steel statue, glides stiffly into view, promising us salvation with the first stretch of motorway. More than 100 miles of the A1 have been upgraded to motorway since the 1960s, given three lanes, a hard shoulder, gentle curves and restricted access to ease travel and push speeds up.

But despite the regular jams, tailbacks and accidents, 21st-century drivers should consider themselves lucky. In 1754, it took 10 days in summer and 12 in winter to travel the length of this road, when a combination of wet weather, poor surfaces and coach wheels produced more mud than traction.

Turnpike trusts were set up during the 18th century to repair important sections, charging travellers a toll to raise the necessary revenue. By 1776, with frequent changes of horse at coaching inns along the way, a coach could make the journey in four days. Things gradually improved and, in 1818, one mail coach reached Edinburgh in 451Z2 hours.

It was engineers like Blind Jack Metcalf, Thomas Telford and John McAdam who made the difference, and they became national heroes. Their efforts to improve road construction included good drainage, a camber to deflect water, a surface of small broken stones and well-laid foundations.

The motor car changed everything. On the one hand, it condemned the railways to a slow decline. On the other, it caused immense damage to even the best maintained road. Surfaces designed for hoof and wheel could not handle fast-moving rubber tyres. In winter, they were mud; in summer, clouds of dust. Legend has it that, in 1901, a county surveyor called E Purnell Hooley chanced upon a stretch of remarkably unrutted road, where a barrel of tar had been spilled on top of a surface made of waste slag.

Hooley patented his discovery and called it tarmac, and the modern road was born.

Today, Edinburgh to London is quite possible within eight hours. But the road that once connected whole chains of villages, towns and cities now actively avoids contact with anything other than fast-moving people. From the uniformly landscaped embankments to the ubiquitous rubbish that garlands brambles beyond the hardshoulder, from the soggy service station sandwich to the standard look of the road signs, there is little on the A1 today to reflect anything of the localities it occupies, beyond the names of destinations and the odd piece of cryptic graffiti.

The trappings and triumphal architecture owe allegiance only to the road itself. But locals do try to stand against the current. Protest groups have sprung up the length of the road, each one attempting to resist an aspect of its tyranny. Ten miles north of Harrogate, we pass Kirby Hill, where a campaign is opposing the construction of a motorway service area. Further south, near Wetherby, an action group is striving to reduce the environmental and social impact of plans to build a new section of motorway. A third group is demanding quieter road surfaces as the road cuts through Welwyn in Hertfordshire.

The A1 has always known protest. Hunger marchers, countryside campaigners, anti-war activists and flying pickets have all taken to the highway. A few years ago, fuel protesters choked the flow of traffic with slow-moving “rolling roadblocks”. Even some of the road’s legendary figures have been moved to mount protest against unwelcome change. The Devil is said to have thrown bolts of molten rock as the ancient king of the Brigantes sought to choose between the new Christian faith and the old druidic beliefs. We pass those bolts - three giant Bronze Age megaliths called the Devil’s Arrows - by the A1 at Boroughbridge.

Just a few miles to the south, we see the road’s loyal shock troops - the construction crews who are working to upgrade another stretch of dual carriageway to motorway. Here we are corralled and bullied by legions of nagging, uniformed traffic cones, every bit as controlling as the Roman soldiers of yore.

We plough on southwards, through expansive farmland. We pass the Newark scrapyard with its decaying jet fighter. We pass Woolsthorpe Manor, where Sir Isaac Newton formulated his idea about gravity. We speed through the village of Stilton, where the cheese makers of Leicestershire came to sell their wares to passing trade. At Stangate Hole, just before Alconbury, we plumb a dip in the road that was once renowned as “the most noted robbing place in all this part of the country”.

As we get close to London, we pass Knebworth House, home to the Victorian novelist Edward Bulwer Lytton, author of the words “The pen is mightier than the sword”. Yet he did not wield that pen in defence of the highway on his doorstep. The musicians who now play in the grounds of Lytton’s house - The Rolling Stones, Oasis and Robbie Williams among them - simply send the A1 grinding to a standstill as audiences in excess of 100,000 clog the road for a few fraught hours. But the A1 is not our Route 66, and none have penned a tribute song in its honour.

The road is drawing to its end. It can’t come soon enough. We run through the suburbs of London, twisting and turning according to the demands of the city that the road is now in thrall to. We barely notice when our route home takes us away before the road reaches its terminus at St Paul’s Cathedral, lost amid the congestion.

The A1 has little of the majesty of a true river and sometimes makes a dirty backdrop to a journey. But it is a great river of goods and humanity that helps sustain our society and economy, linking friends, families and firms together.

l www.teachingideas.co.uk historyromanrd.htm

www.brims.co.ukromans www.channel4.comhistorytimeteamsnapshot_romanroads.html