The steep gradient of Pekařská Street has caused considerable difficulties for tram traffic in the past and has also complicated the traffic situation for cars and trucks. The proposal to solve this situation was part of the so-called fast tram project. Its essence was to build a tunnel under Špilberk Hill, connecting the lower part of Pekařská Street with Joštová Street. The total length of the proposed route was 650 metres and the tunnel was to be 10 metres wide and high. In the first phase of this work, an exploratory so-called left heel tunnel was started in 1978 from Pekařská Street. After the completion of less than 500 metres of the planned route, the entire project was stopped in 1979. It is not clear exactly what the reasons were for this decision, but apparently the planning priorities of the time shifted to other areas and the rapid tramway project lost its relevance. All that remains of the project is an undeveloped gap on Pekařská Street and, at the end of the slope, the entrance to an abandoned adit overgrown with bushes.
The reinforcement made of steel profiles and reinforced concrete slabs is partly corroded and partly deformed by the pressure of the massive overburden. On the walls of the concrete slabs, the white karst formations of sinter deposits that have subsequently formed here shine; others form pools on the bedrock. At first glance, however, it is obvious that the work of driving the adit required considerable effort, as confirmed by the witnesses of this special construction.
The tramway tunnel under Špilberk belongs to the youngest underground structures that were built in the rock massif of Špilberk hill. However, its fate is difficult to estimate today. Although the plan to run a tramway through the rock massif of Špilberk is still open and may happen sometime in the future, it is questionable whether the existing tunnel can be used for this purpose.