25 de Abril Bridge and North Viaduct

25 de Abril Bridge and North Viaduct

🏗️ History and Background

The 25 de Abril Bridge (Ponte 25 de Abril) is one of Portugal's most iconic structures, linking the city of Lisbon on the north bank to Almada on the south. It spans the River Tagus (Rio Tejo) and is often compared to the Golden Gate Bridge 🌉 in San Francisco, USA, due to its similar red colour and design style. In fact, both bridges were built by the same American company — the American Bridge Company — which was also responsible for the steelwork of the Golden Gate Bridge.

Construction began in 1962 and the bridge was inaugurated on 6 August 1966 under its original name, the Salazar Bridge (Ponte Salazar), in honour of Portugal's then Prime Minister, António de Oliveira Salazar. Following the Carnation Revolution on 25 April 1974, which ended the dictatorship, the bridge was renamed 25 de Abril Bridge to commemorate the revolution and the return of democracy 🇵🇹.

Initially, the bridge had only four lanes for road traffic on the upper deck. In 1999, a major modification was completed, adding a lower deck for railway traffic and expanding the upper deck to six lanes. This upgrade made it one of the few suspension bridges in the world carrying both road and train traffic.

The total length of the bridge is approximately 2,277 metres, with a main span of 1,013 metres. Its towers rise to 190 metres above sea level, making it a defining feature of Lisbon's skyline.

Over time, several regulatory changes have been introduced. Originally, only cars were allowed to cross, but later heavy vehicles were permitted under strict limits. Speed regulations, lane restrictions, and toll systems have evolved with technology — from manual collection to the Via Verde automated system.

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🌉 North Viaduct

The North Viaduct (Viaduto Norte) is an essential component of the 25 de Abril Bridge complex, serving as the approach structure on the northern (Lisbon) side of the Tagus River. While often perceived as part of the main bridge, it is technically a separate structure that connects the suspension bridge to the Lisbon mainland. This viaduct spans approximately 945 meters in length and consists of multiple spans supported by concrete piers, designed to handle the transition from the elevated suspension bridge to the ground level road network. The North Viaduct plays a crucial role in distributing traffic flow efficiently between the bridge and Lisbon's urban road system, featuring multiple access points and exits that integrate with the city's transportation infrastructure. Its design complements the main bridge while addressing the specific geographical challenges of the northern riverbank.

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Let´s discuss the 25 de Abril Bridge, focusing only on this specific bridge because it follows particular laws and regulations. The North part of the bridge is known as the "Viaducto Norte,".

First, the 25 de Abril Bridge is classified similarly to a motorway, meaning the same rules apply. Not all vehicles are allowed on the bridge, and speed limits are the same as those on motorways. There are three lanes of traffic in each direction, and a physical barrier separating lanes is mandatory, just as it would be on a motorway. Additionally, the bridge features a reversible lane, meaning traffic in the leftmost lane can change direction depending on the time of day, with signals indicating which direction is allowed.

Now, let's discuss the specific restrictions on the 25 de Abril Bridge:

1. In the event of a breakdown or accident, drivers and passengers should not leave their vehicles. Unlike on other roads where you'd typically wear a reflective vest and place warning triangles, here it's safer to stay inside your car because the bridge is monitored 24/7. Emergency assistance will be sent to you promptly. There are only two exceptions to this rule: if there is a risk of fire or if your car is at risk of falling off the bridge. In these cases, you should exit the vehicle and wait safely behind it, using it as a shield.

2. Vehicles transporting hazardous materials are only allowed to cross the bridge between 2:00 AM and 5:00 AM. This regulation minimizes risks during times of high traffic, ensuring that any accidents involving dangerous materials happen when fewer vehicles are on the road.

3. Driving lessons are prohibited on the bridge. Due to the narrow lanes and heavy traffic, it is not safe and not legal for learner drivers to practice on the 25 de Abril Bridge.

4. Certain types of vehicles are not allowed in the leftmost lane. These include:

   • Light vehicles with trailers
   • Motorcycles
   • Heavy vehicles, whether carrying goods or passengers

   Unlike other motorways where only heavy vehicles are restricted from using the left lane, the 25 de Abril Bridge also restricts motorbikes and vehicles with trailers from using this lane.

🔸 Lane Control and Signalling System

The bridge is equipped with an overhead lane control system that uses illuminated arrows (🟢) and red crosses (❌) to manage the reversible lane. Drivers must always obey these illuminated signals even if the lane appears free. Entering a lane marked with a red cross is considered a serious offence under the Highway Code, equivalent to driving against traffic direction.

🔸 Speed Limits and Wind Restrictions

The standard speed limit is 70 km/h for light vehicles and 50 km/h for heavy vehicles. However, under strong wind conditions (💨), the concessionaire and police authorities may reduce the limit or temporarily ban motorcycles and high-sided vehicles from crossing for safety reasons.

🔸 Emergency Lanes and Cameras

There are no hard shoulders on the bridge, only narrow emergency areas at intervals. Continuous CCTV monitoring allows the control centre to dispatch police or tow trucks immediately when a vehicle stops. Drivers should not attempt to repair vehicles on their own.

🔸 Toll Collection and Payment

Tolls are collected only in the direction from Almada ➜ Lisbon. Payment can be made using Via Verde (automatic), cash, or card. Vehicles travelling from Lisbon to Almada cross free of charge.

🔸 Pedestrian and Bicycle Access

Pedestrians 🚶‍♂️ and cyclists 🚴‍♀️ are strictly prohibited from crossing the 25 de Abril Bridge due to safety and wind conditions. The lower deck of the bridge is reserved for railway traffic only.

🔸 Enforcement and Penalties

Traffic offences on the bridge, such as lane violations, speeding, or ignoring variable messages, are subject to the same penalties as motorway infractions, as defined in Articles 27–30 of the Código da Estrada. Enforcement is carried out through cameras and police patrols at both ends of the bridge.

🎯 Exam Questions

For the driving exam in Portugal, there are typically four specific questions related to the 25 de Abril Bridge that candidates should be prepared for. These questions test your knowledge of the special regulations and restrictions that apply specifically to this bridge.

Watch the following video for a detailed explanation of these exam questions and additional insights about the 25 de Abril Bridge: