"I heard all the petrol stations were running out of fuel so I came to fill up, otherwise I worried I won't be able to get to work tomorrow," said Raul, a driver in Madrid, Spain's capital.
Cepsa, a Spanish oil company, said 45 per cent of its deliveries had failed to get through to stations due to strikers blocking their path at fuel depots, although Repsol, Spain's biggest oil firm, said deliveries were getting through with "relative normality".
Half of the normal number of tankers picked up fuel at depots on Monday, although many oil companies had taken on extra supplies in previous days in anticipation of the strike, CLH, a distribution firm said.
The indefinite strikes over the impact of high oil prices, now at record highs of over $139 per barrel, have also been backed by protests across the border in Portugal and France.
A Portuguese truck driver was killed near Alcanena, north of Lisbon, as he tried to stop a lorry at a road block set up by truckers also protesting against high fuel prices.
Manual Agostinho, a fellow striker who was running the road block, told Portugal's Lusa news agency that the 52-year-old man had been run over by a heavy goods lorry as he signalled for it to stop.
Agostinho said the lorry had been travelling at about 50kph.
"It went over him. It's murder," he said.
In Madrid, truckers caused traffic chaos by slowing almost all roads into the capital, while others blockaded wholesale food markets.
Authorities opened toll booths to ease the traffic around the capital, while Barcelona's city council said it was preparing a plan to ensure supplies of food, fuel and health products were not impeded.
Seat, a car producer in Catalonia, said it stopped production on Monday night and a further two shifts on Tuesday, cutting production by 700 cars a shift, because supplies could not get through.
Other car makers said they had enough parts for several more days production.
Meanwhile, a strike by Spanish fishermen, now in its 12th day, shows no sign of ending with almost all the Spanish fleet still in port.
Only a trickle of fish passed through Vigo in Galicia, Europe's biggest fishing port, compared to the 200 tonnes that is normally traded there every day.
Traders at Madrid's main food wholesale market said that supplies of fresh food would start to run out in the coming days.