Vienna — These days, the Hungarians don't illuminate the Great Chain Bridge over the Danube River at Budapest with little lights when Austrians go visiting. There is no longer an Austro-Hungarian Empire. Nor is there an emperor in Vienna and his empress, who was also a much-loved queen of Hungary, to be honored on gala visits to the capital.
After World War I, Austria and Hungary took on new identities as separate republics. Today, Austria is neutral, posed between East and West, and Hungary is a member of the Soviet alliance.
But in recent years, the welcome mat for visiting Austrian and Hungarian leaders is being put out in prewar fashion. The two countries have developed a mutually profitable relationship that is closer in substantive, practical terms than in the days of the empire.
Tentative rapprochement began in the 1960s when Austria moved to initiate contacts. Later it invited Hungarian Communist leader Janos Kadar for his first visit to a Western country.
The new links gained further strength four years ago, when Vienna and Budapest decided to open their common frontier. It was the first time that people without visas could cross into an East-bloc country directly bordering on the West.
Last year, almost 1 1/2 million visa-less Austrians visited Hungary. Of the half-million Hungarians who traveled to the West, about 200,000 of them came to Austria. That half million was easily the biggest number from any East-bloc country.
Government exchange visits became a reestablished pattern long ago. And new Austrian Chancellor Fred Sinowatz's first visit to Budapest late last year capped a cooperation package that included a number of industrial projects.
Twenty leading Austrian businessmen accompanied Mr. Sinowatz to Budapest and stayed on to discuss a role in hydro-power construction on the Hungarian-Czech section of the Danube River. They also talked about helping Budapest modernize its telephone exchange system and various other industrial undertakings.
Some 600 Austrian firms now have business links with Hungary. They have more than 100 active industrial cooperation arrangements - some for joint projects in the third world.
In 10 years, trade has risen 2 1/2 times to between $500 and $600 million. A fast-growing border trade put another $40 million into Austrian business pockets last year through direct sales to Hungarian department stores and other consumer outlets. Cooperation is reaching into culture and education. There are plans for university student exchange and teacher training.
''There is no longer an 'iron curtain' between us,'' Mr. Kadar told the Austrian chancellor.
And so it seems, with people from either side moving up and down the Danube by steamer and hydrofoil about as freely as the imperial yacht took Franz Josef and his consort about a century ago.