OF ALL the world's travel bargains, few can compare with the Japan Rail Pass - even though it may seem expensive at first glance. At JPY27,800 (HK$1,900) for a seven-day Ordinary Pass, the JRP is not cheap at current rates of exchange, but neither are Japan's regular rail fares, so the savings for foreigners can be significant. A Japanese would have paid well over JPY70,000 for a seven-day rail trip I recently went on. As a pass-holding foreigner paying JPY27,800, I saved almost 60 per cent. Wonderfully, the cost of the rail pass is recouped with just one shinkansen Bullet Train return trip to the Osaka region. ''Ordinary'' carriages on the shinkansen trains or other high-speed services would be considered luxurious in most other lands. Travellers who feel uncomfortable in anything other than first-class conditions can gain them with a Green Car (''superior-class'') rail pass. It costs JPY37,000 for seven days of travel, and is still worth it. Japanese executives pay more for one Green Car reclining-armchair ride to Kobe and back. Passes with longer validity are also available. The 14-day Ordinary Pass costs JPY44,200 (JPY60,000 for Green), while 21 days of unlimited travel will set you back JPY56,600 (JPY78,000 for Green). Prices are halved for children aged six to 11 (under sixes travel free provided they sit on their parents' laps). Incredibly, the passes' yen rates have hardly changed for years: the seven-day Ordinary Pass went up just JPY800 when it was last revised in the 1980s. I was so impressed by the pass's cost-effectiveness on my seven-day trip, I then planned a 14-day trip going off the beaten railway tracks - right off them on days when I had to use mountain buses and ferries. The tour of central Honshu and southern Hokkaido would have cost a Japanese rail traveller JPY76,500. I'd saved over 40 per cent. Scheduling a self-planned rail tour is no problem. There are three shinkansen lines (all connecting at Tokyo Central station), and a total of 23,000 trains run daily on the 21,000 km of track belonging to the Japan Railways (JR) group, the revamped version of Japan National Railways. Helpfully, the Japan National Tourist Organisation (JNTO) publishes a 24-page English-language Railway Timetable that lists the scheduled services on 46 main lines, and seven for major private lines. With so many train services available, advance planning is not usually necessary, unless your itinerary is extremely tight or you travel during weekday rush hours and holiday peak periods. At those times, advance seat reservations are essential for the shinkansen Super Express (SPX), Express (EXP) and Limited Express (LEX) services, especially if you want window seats or no-smoking carriages. The rail pass voucher is only issued outside Japan; validation can only be done in Japan. Your passport is checked, to ensure that you are a bona fide non-Japanese visitor. Once the card is issued, you are made to feel like a VIP at the JR Travel Service Centres. Open until late at night, they provide complimentary seat reservation and travel information services. JR's computer systems are astonishing contraptions of massive metal ''pages'' and pegs, reminiscent of old-style weaving looms. The punctuality of the country's rail system gets taken for granted. If your connecting train leaves ABC at 17.54, you can safely plan to reach there at 17.47, because no JR train I took was late. You can set your watch by the trains. Even if you cannot see a station's English-language nameboard, if it's 14.17 you know from the timetable that you are at XYZ. English-language signage is clearly evident throughout the rail network, and more so than before on local routes and urban subway systems. Admirably for a supposedly chauvinist land, Japan's shinkansen and major express services provide taped English-language announcements on board and on station platforms. Disappointingly for speed freaks, the astonishing fact of travelling at up to 240 km/h is no longer sensed in the new-style carriages. Instead, it is merely a talking point for foreigners in the buffet cars, where a speedometer electronically clocks up the high-speed reality. Zipping along the tracks, the sound-proofed, carpeted shinkansen carriages do not sway, rattle or roll. Silently, the ''bullets'' shoot straight ahead or purr round cambered bends, and my only complaint about them is their temperature - always hot and dry. Courteous service produces courteous customers: Japan's train passengers are unlike any others. They scrupulously make use of litter bins, smoke only where they may, and rarely make loud noises. However, if allowed to, they will politely exhaust foreigners with endless English-practising question-and-answer sessions. In self-defence, if you travel alone, wear earphones. So the Age of the Train is still alive and well and wonderful in Japan? ''Wonderful'', yes. ''Well'', no. The short-distance private lines (mostly commuter-filled and property-rich) are profitable, but JR's country-wide efficiency has cost Japan's tax-payers a fortune. Even Japan cannot blend old-world standards, old-style unions and profit consciousness. Consequently, visitors who take advantage of Japan Rail Pass bargains are doing their bit to dent Japan's economic miracle. The joy is that one can see that miracle - and Mount Fuji and Japan's other scenic glories - through the train windows. They are, of course, always clean. Japan Rail Pass vouchers can be obtained from various specified agents in Hongkong: contact your travel agent or airline for details. Vouchers, valid for three months, can be validated at Tokyo's Narita International Airport, and in many provincial cities'railway stations. Holders of Hongkong passports require visas for Japan.