Twenty-one years ago, Simon Calder hitch-hiked his way across Europe from London to Poland. This year, armed with his 1984 guidebook, he attempted the same trip - and discovered a world of difference

Twenty-one summers ago I thumbed across Europe to Poland, location for the world's only official hitch-hiking scheme. In the 21st century, the Social Autostop Committee and its fine philosophy have gone the way of state communism. But is it still possible to cross the continent relying almost entirely on the kindness of strangers? This year I took to the roads again to traverse northern Europe by thumb. And for company, I took the 1984 Hitch-hiker's Guide to Europe - £2.95-worth of sometimes dubious advice for impecunious travellers. Try this: "For sleeping rough in London, a good place is on the embankment near Westminster Bridge. The police move you on at about 6am." These difficult days, a little quicker than that, I fear.

In 1984, the car-rental company Hertz had a splendid scheme to get you from London to Dover for a nominal £1 plus a bit for petrol. Because so many motorists were returning to the port from the Continent sans voiture after accidents or breakdowns, there was a constant shortage of cars at the Dover depot. Accordingly, the branch of Hertz at Russell Square in central London would rent you a vehicle for the one-way drive for one pound. The company even threw in a free ride from its Dover depot to the Eastern Docks. Here, you could buy a day return to Zeebrugge for £11, even though it was obvious to everyone that you had no intention of returning the same day.

Today, the car-delivery trick has ended, the ferry route has been abandoned and shipping lines are attuned to day-return "tariff abuse". So I started my hitching trip by travelling through the Kent countryside at 186mph - not along the M2, but on the Channel Tunnel rail link, thanks to a cut-price Eurostar deal to Lille. Unlike in 1984, which I recall through an exhaust-filled haze of autobahnen, my plan was to dawdle. My eastbound course would be punctuated by seeing the places I missed last time. The pretty way, if you like.

"Pretty" is not a word you would use to describe the outskirts of Valenciennes, where I left the station to start my adventure. (By now you may be thinking that, for a hitching trip, there is a lot of rail travel involved; but if you have ever tried to hitch out of the autoroute entrails of Lille you will understand the benefit of a short, cheap train hop.) One drawback with hitch-hiking: you see more than you might wish of the dismal parts of towns, rather like going to Walt Disney World but spending much of your time in the car park. The other hindrance is that you are entirely reliant on fellow humans.

Naturally, the hitch-hiker tries to improve the odds by choosing a road with plenty of traffic heading in the right direction. Now Valenciennes is a modest northern French town that should, by rights, be no harder to find the way out of than, say, Canterbury. But it has had the builders in for most of the year, and by following a sequence of diversion signs I managed to make a long, ham-fisted circuit of the town. I ended up at a roundabout that linked the roads from an out-of-town entertainment complex to a building site. "Ever get that never-gonna-get-a-ride feeling?", the chapter on France in the Guide enquired cheerily. It did not look jolie. All the known laws of hitch-hiking point to this being a hopeless position. An hour earlier, I had been travelling at 186mph. My speed had fallen to zero with no prospect of an imminent improvement - until Kevin lurched to a halt in a Renault that was older than he was.

Hitch-hiking provides more than free travel: it propels you into a series of arbitrary encounters with people who you would never otherwise meet. Most of us live in small worlds, with few opportunities to find out about different lives. But I was about to share half-an-hour of the world according to Kevin. He was a French soldier whose experience of Britain was limited to a school trip to Canterbury. But he had enjoyed two years in Tahiti at the taxpayer's expense; Polynesia is not regarded as one of the more arduous or dangerous postings for the French army.

The efforts of the pale sun to burn though the clouds over Picardy eventually paid off. Church steeples perforated a horizon the tone of parchment, while the dappled foreground had drifted in from a Van Gogh landscape. A hitch-hiker's privilege is to admire the scenery free of the responsibility of driving, while the lift-giver's prerogative is to chain-smoke. Kevin drove me about five Marlboros across northern France, dropping me on the doorstep of Belgium.

Hitching near frontiers used to be notoriously poor - partly because traffic dwindled, and partly because drivers' folklore told of hitchers smuggling drugs and, if caught, blaming it on the driver. Now, though, the only indication that you have moved from one nation to the next is a road sign. Hopping into and across southern Belgium was hitch-hiking heaven: polite people guiding shiny new hatchbacks along well-kempt roads through picture-book scenery. At tidy junctions, there was barely time to take in the order of the new surroundings before the next ride turned up.

The soundtrack of Europe was improving, too. After Kevin's crackly radio, ill-tuned to a station broadcasting its queasy quotient of French pop, I enjoyed a CD of classical greats as far as Charleroi, then an i-Pod-meets-cassette-player device playing Franz Ferdinand from there to Namur. Walloon tunes, indeed. I ambled through the cobbled old town of Namur, the capital of Wallonia, where the Meuse meets the Sambre in dramatic fashion. A medieval citadel tops the outcrop of rock at the confluence of the rivers: quintessential Europe.

Liège was the first proper confrontation with my hitching past. The ideal way to see this handsome city is while whizzing along the highway that clings to the Meuse. That was how the place had struck me the first time I hitched through here, as I recall on a rollicking ride to Maastricht in southern Holland. What you do not want to do in any city is to get dropped off at the wrong end of town: the side that you come in on, not the one you wish to leave from. But beggars of lifts cannot always be choosers. I called it a day and checked into a hotel - on this trip, I opted not to camp.

The motorway entrances at Liège are no longer scarred in the way they were. Stand in one* *hopeless place long enough, and you too may be tempted to carve a bitter message on the crash barriers. The set of barriers beside the highway to Aachen were unsullied. As Europe is almost bereft of hitchers these days, the ghostly autographs are nowhere to be seen. Or perhaps, I speculated as I clambered into a silver BMW with German plates, it's because we get lifts so easily.

Self-delusion, I'm afraid. Several things have happened to reduce the numbers of hitch-hikers to the status of an endangered species. First, the economic imperative for thumbing has dwindled in much of the Continent. Increased wealth means students - who used to be the scruffy stormtroopers of hitch-hiking - are often driving cars themselves rather than standing wanly by the road. And low-cost flights have rendered hitching economically irrational for many journeys - the one I was making, for example. Book in advance for a no-frills flight from London to Krakow in southern Poland, and you might pay as little £25. The train ride and hotel stay had cost me much more than that, and I had got only as far as the western edge of Germany. The existence of cheap flying has forced rail operators to cut fares, too - Deutsche Bahn, which runs the densest network of trains in Europe's biggest country, has capped fares within Germany to a maximum of €111 (£80). That is for "walk-up" fares; buy ahead and you pay far less.

Happily, the Germans have not surrendered their role as the most generous lift-givers in Europe. On the Continent's oldest motorway network, you can regard each rastplatz as merely a place to change vehicles. "A hitch-hiker's hell on earth" is my guidebook's description of the Ruhr. But so good is 21st-century hitching, or so lacking is the competition, that you find yourself tutting if an old truck or a small Beetle stops beside your thumb.

In 21 years, linguistic skills have improved no end. Not mine, you understand; every driver in Germany seems to have a good working knowledge of English, so I was never obliged to call upon my rusty German motoring vocabulary. I was able to discuss Europe (less and less popular the further east you go), Iraq (universal condemnation of the invasion) and next year's World Cup in Germany - thankfully before England's humiliating defeat at the hands of Northern Ireland.

Since the Iron Curtain rusted away, eastern Germany has been transformed. But hitching to Berlin, it has to be said, was a more profound geopol- itical experience a generation ago. When Germany was divided, you were allowed to hitch across the communist GDR to the enclave of West Berlin - but only if you got a lift going all the way. You were not allowed to be dropped off en route, because this would violate the terms of your transit visa.

Accordingly, at the frontier posts on the motorways heading across the divide, you were guaranteed a lift of a couple of hundred miles. Better still, West German motorists regarded picking up hitchers as a moral imperative. So trivial was the business of getting a ride that some cheeky hitchers even held up signs specifying the part of West Berlin they wished to be taken to. I made no such conceit, not least because I wanted to visit Magdeburg - one of the cities that had been nothing more than an Ausfahrt sign.

I was just in time to say happy birthday; the city is 1,200 years old this year, and the authorities have been turning the architectural clock back a century or so, before war and the Soviet Union intervened. At the handsome Theater der Landes- hauptstadt, you can pay your respects to Wagner as a young man; aged 22, he oversaw the catastrophic premiere of Das Liebesverbot here, and bankrupted the venue.

The landscape between here and Berlin is dotted with 21st-century windmills, and the A2 autobahn is impeded with an implausible number of Trabants. Those dreadful cardboard cars, which passed their crush-by date around the time of my first trip, have all the power of a geriatric lawn mower. So much for Vorsprung durch Technik. Thankfully, I made it to the capital without being offered a lift in one.

When leaving a big city, every hitcher has a complex calculation to make. As a rule, the closer you are to the centre the longer you will have to wait for a ride. Conversely, the more you invest in public transport out of town, the easier you will get a ride. (The Hitch-hiker's Guide suggests a variant: travelling on the U-Bahn without a ticket and feigning ignorance when caught: "You might be let off with a warning.") But in rail-friendly Brandenburg - the lande that surrounds the capital, to whose Margrave JS Bach dedicated his concertos - a few euros buys a train ticket almost to Poland.

The last big town in Germany, at least by the route I took, is Stalinstadt - or it was for much of the life of the German Democratic Republic. When the Soviet tyrant fell out of favour, the town was re-named Eisenhüttenstadt and formed a joyful union with my home town, Crawley. On a darkening evening, you can see some scary similarities in clumsily idealistic post-war planning, but (and I never thought I would write this) Crawley definitely has the architectural edge.

The Germanic twin is better for hitching, though. Herman had been born shortly after the war, but since the collapse of communism had been mainly unemployed. The state provided him with enough cash to run a rattly old VW, and he provided me with a lift. As we proceeded alongside the Oder river- which marks the frontier with Poland - he also provided a commentary of disillusionment with capitalism, with Germany and with Europe.

Once across the border, I found animation in place of alienation. No longer did I need the book of hitching coupons provided by Poland's Social Autostop Committee to try to stick out from the gloomy crowds hoping for a ride; they had vanished. The motorway heading east through Wroclaw and Katowice has barely improved in its surface, but the cars that pick you up these days have far better suspension. Their occupants also have the freedom to play Elvis at near-seismic volumes. Presley will certainly be always on my mind, due to the ear damage I think I sustained as we approached Krakow. A little more conversation, please.

The Hitch-hiker's Guide to Europe, 1984,urges you to head further east. "Baghdad is your genuine Arabian Nights city." But the end of the road is nigh, offering the prospect of an atmospheric hike without a hitch, a good dinner (unobtainable at any price in 1984) and a cheap flight home. Here, the talk is of petrol at a pound a litre. Yet why blockade refineries? Use someone else's petrol instead.