**4. Designing and monitoring of sectors and routes**

In this section, we consider the two types of results we obtained by using the OPILM SisRot LIX©. The residential refuse collection and domiciliary selective waste collection results are detailed in the following subsections.

#### **4.1 Household refuse collection**

With a population of 307 thousand inhabitants [30, 31], Petrópolis-RJ is a wellknown touristic city; it has 48 collection sectors with an average of two collection circuits per sector. Five sectors were performed by the concessionaire downtown. The June 2020 data (without optimization) of these sectors were informed by the managers of the local concessionaire as follows:


**Figure 3.**

*Maps indicating the division of operation in downtown Petrópolis-RJ, considering at right previous sectoring (overlapping) and new coverage after project's intervention.*


**Figures 3**–**7** present the planning process to rearrange actual sectors and routes for the concessionaire. The development of the plans considers the unique precedence of

#### **Figure 4.**

*Maps indicating the division of operation on Mondays in downtown Petrópolis-RJ, where on the left, we see the original five sectors (non-overlapping) and on the right, the final optimized sectors.*

*Optimized Planning and Management of Domiciliary and Selective Solid Waste... DOI: http://dx.doi.org/10.5772/intechopen.111432*

#### **Figure 5.**

*Maps indicating the division of operation from Tuesdays to Saturdays in downtown Petrópolis-RJ, where on the left, we see the original five sectors (non-overlapping) and on the right, the final four optimized sectors for these days.*

#### **Figure 6.**

*Sector 220, high variability production between Mondays and Tuesday–Saturdays (more stable).*

#### **Figure 7.**

*Sector 220, above the variability between total distances traveled per trip (above) along the days of the week and variation in time duration (below) between Mondays and Tuesday–Saturdays.*

the garbage (no sector overlapping) and minor changes between days of collection to warranty the monotonicity and completeness of the service.

**Figure 3** presents the state of the planned sectors we found in downtown Petrópolis-RJ; they were covered daily at night. The sectors were planned considering overlapping coverage (**Figure 3** - left), meaning that it was no longer possible to precisely identify the places where the garbage came from. It was necessary to separate the groups to be unique and make the statistics of production (**Figure 4**-right).

**Figure 4** presents the previous (left) and new sectors' (right) configurations for the new spatial division in reason of the optimization of the sectors and routing to be performed on Mondays. **Figure 6** presents the previous (left) and new sectors'(right) configurations for the new spatial division to be performed from Tuesdays to Saturdays with four vehicles only. It can be also seen in **Figures 4** and **5** that the collection is also performed in star points (containers, gas stations, bars, supermarkets, etc) and brown points (called "manual collection"—places where the vehicle cannot come in and/or traverse. It normally stops, and a collector take it manually hundreds of meters away from the parking point).

The practiced routes are performed following a great route between all street segments from garage to transfer station. It means that the driver follows the sequence defined by the great route, and every time the driver wants to discharge (in general because of the vehicle overload), he drives to the transfer station.

In **Figures 6** and **7**, we can see the great difference between the garbage production, distance, and time on collection for sector 220 by the city on Mondays (due to higher flow of commerce on this day) and the rest of the week. It achieves about 50% of the production between these days in downtown Petropolis-RJ, and it indicates that the service plans must be distinct for each period (Mon and Tue-Sat). For Tue-Sat, the dispersion of the garbage is very low.

**Table 1** shows the scenario of the production practiced in each sector before the optimization. It is convenient to observe more precisely the variations between each sector on Monday.

Our field evaluations had been done in just one scenario, in case of the service movements realized for Tuesday–Saturday, because it may be extended for Monday, after adjusting the street coverage and special local constraints needed to be satisfied (one-way streets, passing more than once in particular streets, passing particular places in a specific time, manual collection, and others). The project identified all the turns and prohibitions during a period of 35 days.

After identifying unfeasible movements, many of them were lost because they were not properly identified. We prepared the drivers in the use and navigation of the CherryTrack®LIX for a week, and then we started evaluating the routes in the next week. We tried four times to run the plans in plain use. The first time, we evaluated the completion of the routes and use of CharryTrack® Lix by the drivers. Problems with the constraints (turns and prohibitions) and with the response of the app were detected that disturbed the execution of the routes, leaving many streets without coverage. On the second try, we had problems with changes in the field not being reported, vehicle overload before expected, and still matters with the app response. On the third try, we had problems with vehicle overload before expected and no more problems with the app response, and finally, on the fourth try, we only had problems with tire flat and no more, although a new change was necessary in the routes asked on the last day. The evaluations were done from October/2021 to January/2022.



*Optimized Planning and Management of Domiciliary and Selective Solid Waste... DOI: http://dx.doi.org/10.5772/intechopen.111432*
