Iraq is rushing construction of a two-lane, hardtop road through the desert of Iran's oil-rich Khuzestan Province to this beleaguered city, an all-out effort providing the most visible sign that Baghdad is preparing for a long war.

The 60-mile desert route, traveled today on a spine-cracking ride mostly along rutted, dusty tracks, looks like a film set for Rommel's World War II campaign in North Africa.

While the provincial capital of Ahwaz remains "surrounded on three sides," according to an Iraqi military commander today, engineers and equipment operators wearing kaffiyeh headdresses are working at amazing speed to build a road to carry troops and armaments more easily into Iran.

"We are building the road to provide facilities for the forces," said an Iraqi Army Colonel commanding one sector of heavy artillery and tanks around Ahwaz.

It looked today as if the roadbuilders were proceeding more vigorously than the military.

Three weeks ago according to reporters who visited this area, there was no sign of road construction along the rutted tracks they took through the desert.

Today, however, the signs were everywhere. There were at least 200 pieces of heavy earth-moving equipment, graders and packers scattered along the route. The construction work was all being done by civilians. It looked as if much of the country's road-building equipment and talent was thrown into the effort.

By Western standards, the road may not be much. In this part of the world, however, it will be the equivalent of the Baltimore-Washington Parkway.

It is, therefore, not something the Badhdad government would enter into lightly.

The massive numbers of Iraqi tanks, armored personnel carriers, artillery pieces and trucks that are besieging Ahwaz came here over the desert route, and more heavy artillery was seen moving to the front today.

But the rainy season is due to start late next month. The fine desert soil that blows in clouds making visibility nearly impossible will get churned into a sea of mud that could stall the supply of military equipment to this area.

The new road is being hardtopped as segments are completed. In fact, some parts of a hard-packed dirt segment finished this morning had been given a light layer of tar by late afternoon.

As the road builders worked today, trucks, oil and water tankers, jeeps, other four-wheel-drive vehicles and tank transporters crisscrossed the desert trying to stay out of their way.

The road leads out of Iraq, north of the port city of Basra, runs parallel to and inside the Iranian border past three gendarmerie border posts -- one, at Ghazeybel, looking like a fort from an old French Foreign Legion film -- until it cuts northeast through the railroad town of Hamida, 200 miles southwest of here toward this besieged city.

Ahwaz, which is still held by Iran, contains the computer that controls pipeline activities for the National Iranian Oil Co. It used to be the center of Iran's oil business, which until the war started four weeks ago provided the hard currency needed to buy foreign goods.

Iraqi troops are about five miles from Ahwaz, said an Army colonel, who refused to give his name. The colonel, a member, as most Army officers are, of Iraq's ruling Baath Party, said his troops are waiting for orders to assault Ahwaz. He added that he felt confident they could take the city within two days.

But no infantry, which would be needed to storm a defended city, was seen either in his headquarter's encampment or in others visited along the way.

This seems to be a war of artillery, and judging from today's visit to a front, a very desultory one. In two hours spent here, there was less than a dozen rounds fired toward Ahwaz.

On the other hand, the Iraqis are well dug into positions. Their tanks and artillery are scattered around the desert encampment to make it harder for them to be hit by artillery shells or air raids.

The colonel talked to the foreign journalists in his bunker, which was dug five feet deep and had an armored personnel carrier parked above it as roof and shield. As he talked, aides passed around an orange drink and dates from a box marked, "From the Garden of Eden."

He said his troops were in a good position to assault Ahwaz when they get their orders. He claimed continuous fighting on the front and said his men destroyed five tanks yesterday, losing one of their own. There were, however, no signs of a tank battle nearby.

He insisted Iraq is aiming purely at military targets in Ahwaz, not at residents of the city, largely Iranian Arabs who Baghdad says really belong in an Arabian state rather in Persian Iran. The colonel called this part of Iran "Arabestan," a name for an independent state of Iranian Arabs in Khuzestan, the creation of which some observers believe is Iraq's real aim in this war.

"We believe this land is an Arab land and Iran is an aggressive, racist state," said the colonel, echoing the Baath Party line. "We did not begin the war. Iran did and we answered. Now Iran is destroyed politically, militarily and economically, and the world knows that."

Asked, in view of the tenacious resistance put up by Iran, whether Iraq might not be building the desert road only to eventually turn it over to Tehran, he replied, "I don't think so."