## 3 The Concept of Area-Based Vehicle Speed Control
### Preliminary Field Research  
The Stare Babice municipality is one of the municipalities with a relatively large budget, which in 2025 is approximately PLN 256 million (around USD 70 million). According to the municipality's tasks, a portion of this amount is allocated to enhancing security in the broadest sense. This includes enhancing traffic safety through targeted investments in various types of infrastructure. Among them are radar speed meters, which are being installed in places of particular importance (such as the vicinity of schools). However, they are not used to punish drivers but only play an informative and educational role. They display the measured speed on large screens. Depending on whether it is higher or lower than the speed limit, it is shown in green or red. Additionally, a caption is displayed, stating \"thank you\" or \"slow down,\", respectively. Some solutions also display an emoticon, i.e., a smiley or worried face. The distribution of speed displays in the municipality is illustrated in Figure 3, and the appearance and location of some of these displays are shown in Figure 4.  
The effectiveness of this type of solution is debatable and has been the subject of many studies and analyses. The prevailing view is that this solution is not very effective and has only a short-term effect on drivers in local traffic. After some time, these drivers, so to speak, become accustomed to the presence of displays and disregard their messages. All the more so because this is facilitated by the lack of a penalty for speeding; however, this solution is relatively cheap, and this is its main advantage, especially since it certainly does not negatively affect traffic safety. The fact that a rather significant accumulation of speed displays exists in one municipality and in a relatively small area was used to undertake the first preliminary field research. In May-June 2025, during the morning and afternoon rush hours, as well as midday traffic calming, the values of vehicle speeds were recorded by the displays. Subsequently, the data were systematized and saved in files of a simple database. This enabled both the analysis and presentation of the data. Example results from detectors SD_02 and SD_07 are shown in Figures 5 and 6. The green color indicates the results that  
Figure 3: Distribution of speed displays in the Stare Babice municipality (source: own elaboration using QGIS). do not exceed the speed limit. The blue color indicates those that exceed the speed limit by no more than 10 km/h. The red color is the result of exceeding the speed limit by more than 10 km/h. Even a preliminary assessment of the results is cause for concern, as it shows not only significant but also numerous speeding violations. This is particularly evident in the case of the SD_02 detector, which is of concern due to its location near a school. For this reason, the area has a speed limit of 40 km/h. At the site, the average recorded speed exceeded 52 km/h, and the maximum recorded speed reached as high as 73 km/h. Very similar results were obtained for the SD_07 detector, which was over 56 km/h (average speed) and 84 km/h (maximum speed), respectively. Both detectors recorded values for which the averages and medians are above their limits (40 km/h and 50 km/h), suggesting frequent speeding on both sections, with a more pronounced violation for SD_07. The slightly higher standard deviation for SD_07 (by 0.43 km/h) indicates a somewhat higher dispersion of speeds, which is consistent with the broader range (30-84 km/h vs. 21-73 km/h). The values for SD_02 exhibit a slight leftward curvature, indicating a higher proportion of  
Figure 4: Example of the appearance of speed displays in the Stare Babice municipality (source: own elaboration). Figure 5: Measurement results for the SD 02 detector, 40 km/h speed limit (source: own elaboration). vehicles with lower speeds (e.g., below 46.75 km/h), whereas for SD_07, the distribution is almost symmetrical.