# Solutions to the Problem of Freight Transport Flows in Urban Logistics
## 2 Materials and Methods
### Theoretical Aspects of the Flows of Freight Road Traffic in the Urban Logistics System
Another researcher [22] studied the impact of freight transport on CO2 emissions. In their research, they relied on data from the French Environment and Energy Agency (ADEME). Table 1 shows a table of ADEME data showing the distribution of CO2 emissions by weight of freight cars. \begin{table}
\begin{tabular}{l l} \hline \hline
**Cars by Weight** & **CO2 Emission (g/tkm)** \\ \hline Small commercial vehicle (1.5–3.5 t) & 1103 \\ \hline Cars (6.1–10.9 t) & 435 \\ \hline Cars (11–21 t) & 221 \\ \hline Cars (21–32.6 t) & 196 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: CO2 emissions of different types of freight vehicles [22]. A total of 82% of the cargo was also found to reach the city by low-capacity transport; the rest is transported by heavy duty freight transport [22]. The examples presented show that freight transport is unevenly distributed in a city logistics system. The use of freight transport in urban logistics is due more to the capacity and legal regulations in the urban area. In a city's logistics system, there are possible restrictions on the movement of goods and heavy vehicles and restrictions on driving on weekends and during appropriate hours. The load on the axle may also be limited, taking into account the existing state of a city's infrastructure, such as street surfaces, bridges, historical heritage, etc. City logistics is dominated by freight transport with a carrying capacity of up to 3.5 t, but the use of heavy-duty transport is also unavoidable, causing the most problems, especially during peak hours, of possible traffic jams, noise, and increased emissions due to braking, increasing traffic jams or the number of controlled traffic light intersections. Researchers [21; 23] have proposed the application of a two-tier hyperconnected urban logistics system, which, according to the authors, would help reduce heavy traffic in cities. This proposed optimization model is based on the idea that cargo from various customers could be consolidated in terminals near cities and transported by heavy transport to small distribution centers in urban areas, from where it would be distributed to recipients by urban commercial transport. According to the researchers' proposal, large terminals in the countryside could be connected with smaller terminals in urban areas, to which transport transporting consolidated cargo would go, and distribution would be carried out by city-friendly, ecological, and small-capacity urban freight transport. According to the researchers, this would reduce heavy traffic in cities [23]. Another way to optimize transport flows in a city's logistics system is the \"sharing economy\". In this context, it is a very broadly interpreted concept, as it can cover both the sharing of vehicles and serviced routes. Such an \"exchange\" would enable transportation and logistics companies to transport more cargo faster in a more environmentally friendly way at a lower cost. Favorable conditions would be created for better utilization of resources, optimization of routes, simplification of schedules, and reduction in carbon dioxide emissions. It should be noted that, in addition to greater operational efficiency, the sharing of available and underutilized resources would allow solving problems related to the overloading of the transport system and the lack of drivers. In the area of warehousing, the sharing economy aims to increase the utilization of existing shared customer warehouses. Finally, the sharing economy presents new and creative ways to start a business and increase efficiency through on-demand staffing models and shared logistics services [24]. The distribution of freight transport in a city depends largely on the characteristics of the traffic network, for example, the road category, number of movement lanes, organization and regulation of movement, organization of stopping places, parking capacity, etc.