The sight of an Israeli family driving through the occupied West Bank on a leisurely outing is becoming increasingly rare as tensions rise among Arabs and Jews over the up-and-down negotiations for peace between Israel and its neighbors.

Along the broad, tree-lined streets of Jericho, whose colorful marketplaces once were crowded with Israelis on a warm Saturday afternoon, it is unusual to see an Israeli-owned car with its distinctive yellow license tag.

The same is true in the bustling, traffic-clogged streets of the Arab town of Ramallah, where not long ago Israelis used to venture for bargain prices on clothing and fresh produce.

The pebble beaches of the Dead Sea, which used to be packed with Israelis almost as thickly as Long Island's Jones Beach, are much less crowded now. Israelis still go there to smear their bodies with the black, sulphide-rich mud and float languidly in the bouyant water, but more often than not they are outnumbered by Arabs and foreign tourists.

The trend of Israelis to stay away from the West Bank, which has evolved gradually over the last several years but accelerated since the Camp David summit conference, is rooted in suspicion, fear, uncertainty over the future of the area and fundamental sociological differences that have been magnified by the tension that has accompanied the turbulent peace negotiations.

Dani Shachal, the military governor's staff officer for West Bank tourism, said another reason is that the novelty has worn off for Israelis in the 11 years since the area was seized from Jordan.

Shachal said no statistics are compiled on the number of visits because of the large number of uncontrolled entry points. But Israeli military and civilian authorities clearly are concerned about the shrinking volume, although for differing reasons.

Some West Bank occupation authorities say they are concerned because the presence of Jewish civilians in the occupied area -- rather than causing security problems -- actually makes the job of maintaining order easier.

The ideal of Jews and Arabs peacefully mingling and shopping together in Arab towns creates a stable atmosphere, the authorities say, that is preferable to the appearance of a Jewish civilian in an exclusively Arab neighborhood.

Israeli political officials, on the other hand, say they are concerned because the key to the success of Prime Minister Menachem Begin's West Bank autonomy proposal is the peaceful coexistence of Arabs and Jews, and a constant movement of the two groups between Israel proper and the territories, seized during the 1967 war.

Foreign Minister Moshe Dayan made that point last September,saying: "I am not a foreigner on the West Bank. And I don't want to be considered a foreigner. I should always have a right to take my car and my grandchildren and go to Jerico if I want."

Right now, the flow seems to be a one-way street. Nearly half the West Bank's 90,000 Arab workers hold jobs in Israel, even if they are jobs that many Israelis have come to shun -- day labor, unskilled construction work and the like.

Moreover, an Arab driving to Israel in an automobile with the tell-tale blue license tag does so knowing the trip will include obstacles. He can count on being stopped at least once -- and usually more often -- at Israeli army roadblocks, where soldiers brusquely check identity cards and search for weapons and bombs.

However, in the other direction, there normally are no such obstacles.

The decline in Israeli visitors to Arab towns has its exceptions. The markets and antique shops of Bethlehem and nearby Beit Jala, both Christian Arab towns near Jerusalem, are still crowded with Israeli tourists on Saturdays.

Also, there are six Jewish settlements within a 12-mile radius of Jerusalem, accounting for some of the Israeli traffic in these towns.

Hebron, with its Tomb of the Patriarchs that is holy to Jews and Moslems, is still one of the country's top attractions to Israelis, although they tend to visit the ancient tomb and then leave, rather than linger in the Arab town.

Some Israeli businessmen with interests on the West Bank say privately that they prefer to bring their Arab clients to Tel Aviv or Jerusalem, rather than make regular visits to the West Bank -- not so much out of fear of imminent danger as just a growing discomfort there.

The near absence of Israelis in Jericho is a startling contrast to five years ago, when so many Jews went there to shop that Israeli merchants complained loudly that their businesses were being hurt.

Ramallah, where average prices are considerably lower than those in Jerusalem, is almost completely boycotted by the large nearby Jewish community of New Yaacov, whose residents prefer to make the drive to Jerusalem to do their shopping.

An Israeli journalist who visits the West Bank daily as part of his reporting duties said he has become accustomed to hostile remarks. He recalled that when he recently visited a vegetable stand in Ramallah's open-air market, the Arab merchant asked, "Don't they have these in Israel?"

And at Kiryat Arba, the largest Jewish settlement in the West Bank, all but a handful of the 1,700 residents do their shopping in distant Jerusalem instead of adjacent Hebron.

West Bank officials say there is a possibility that when autonomy negotiations begin and the contrast between the Palestinians' demand for a sovereign state and Israel's proposal for self-rule on a short leash comes more clearly into focus, tensions may increase even more and the sight of an Israeli family outing on the occupied area may become even rarer.