This video includes a road crossing of the Friendship Bridge, starting from about 3:04 in:
This video starts with a black and white photo of the railway:
A video of the road from Hayratan to Kabul in 2009; no trains though:
Some Soviet photos of the Friendship Bridge and Hairatan, showing the railway.
A Soviet map from 1985 showing the railway line to Kushka – Кушка – extending across the border to Towraghondi – Турагунди – in Afghanistan.
The pink and dotted line is the border, with Afghanistan to the south and west, the USSR to the north.

The RIA Novosti news agency has various photos online, including these showing officials at the formal opening of the Friendship Bridge between the USSR and Afghanistan on 11 May 1982, and Soviet military use of the bridge.
Secretary General of the Central Committee of the People’s Democratic Party of Afghanistan, Chairman of the Revolutionary Council of the Democratic Republic of Afghanistan Babrak Karmal and First Secretary of the Central Committee of the Communist Party of Uzbek Soviet Socialist Republic Sharaf Rashidov at the opening ceremony of the highway and railroad bridge between the USSR and Afghanistan.V. Chistiakov, 11.05.1982
Babrak Karmal, general secretary of the People’s Democratic Party of Afghanistan and chairman of the Revolutionary Council of the Democratic Republic of Afghanistan, at the ceremony opening a motor and railroad bridge between the Soviet Union and Afghanistan.V. Chistiakov, 11.05.1982
Automobile and rail bridge across Amu Darya River between USSR and Afghanistan. The bridge is 816 meters long.V. Chistiakov, 11.05.1982
A Soviet freight train at Hayratan, with freight being unloaded from railway vans into custom-painted lorries:
Unloading humanitarian aid from Soviet Union. Hairaton port. Democratic Republic of Afghanistan.V. Zupharov, 01.08.1986.
And the road at the time:
The road from Hairaton to Kabul.V. Kiselev, 01.10.1989
The Soviet withdrawal:
The first military convoy crosses the Friendship Bridge over the Amu Darya River during the Soviet troop pullout from Afghanistan.V. Kiselev, 18.05.1988
The last Soviet combat vehicle leaves Afghanistan. The USSR conducted a full pullout of its limited troop contingent from Afghanistan in compliance with the Geneva accords.A. Solomonov, 15.02.1989
Back to homeland. A welcome ceremony for Soviet troops returning from Afghanistan near Termez, Uzbek Soviet Socialist RepublicAlexander Liskin, 06.02.1989
Soviet troop withdrawal from Afghanistan. Soviet troop column returns to homeland.V. Kiselev, 01.02.1989
On a railway-related subject:
On November 1986 Moscow customs officers found 1217 of hashish in a railway container which was bound from Afghanistan to FRG. The owner of contraband goods is American company Specific International. The drug was destroyed at the training ground of the Fire Inspection Administration of the Moscow region in the presence of Soviet and foreign journalists.Yuryi Abramochkin, 13.10.1987
Just south of Termez, at Heratan, on the Amu Darya river, diplomats understand that a reinforced steel bridge is being constructed. The aim, it would seem, is to improve the roads and garrison facilities right from the Soviet border to KabulRussians switch to commando-type raids in Afghanistan, Karan Thapar, The Times, 19 September 1980, p1 and p6 (Issue 60728; col C)